yo mx,
I'll list the DTCs that I have info on now and try to find pin-pointtests later; but my 96 Bronco EVTM that had the testing didn't work on WIN 8 or 8.1 PCs or laptops, so I gave it away.
DTC P0133 - HO2S Sensor Circuit Slow Response (HO2S-11) The HO2S monitor checks the HO2S sensor frequency and amplitude. If during testing, the frequency and amplitude were to fall below a calibrated limit, the code will set; Possible Causes: Electrical: · Shorted/open wiring · PCM Induction System: · MAF sensor (On 4-cylinder engines, if P0133 is present, this could be caused by a MAF issue - on 6- and 8-cylinder engines, this could only be a MAF issue if P0133 and P0153 are both present) · Inlet air leaks (unmetered air) Fuel Concerns: · Poor fuel quality Base Engine: · Exhaust leaks (upstream or near HO2S) HO2S Concerns: · Contaminated HO2S sensor (contamination from the use of silicone-based cleaners and sealants, leaded fuel, excessive oil consumption - Deteriorating HO2S sensor; OBD II Response Rate Monitor: The OBD II Response Rate Monitor (P0133/P0153) is only run at vehicle speeds between approximately 50-95 km/h (30-60 mph), during steady-state conditions. The test lasts approximately 6 seconds. Therefore, P0133/P0153 cannot be diagnosed at idle in the repair bay...Most replace the O2 Sensor; but ck for wiring/connector/harness damage and other likely and no $ parts replacement checks 1st; incl testing the sensor ckt; fuses, heater ckt, etc. Fords naming convention is that bank one is the same bank as where the number one cylinder is sensor one is before the cat sensor two is after the cat.
Source: by miesk5
DTC P0133 - HO2S Sensor Circuit Slow Response (HO2S-11); "... The HEGO Monitor checks the HO2S Sensor frequency and amplitude. If during testing the frequency and amplitude were to fall below a calibrated limit, the test will fail. Contaminated HO2S sensor. Exhaust leaks. Shorted /open wiring. Improper fueling. MAF sensor. Deteriorating HO2S sensor. Inlet air leaks. Access HO2S test results from the Generic OBD-II menu to verify DTC..."
Source: by slingblade
================
DTC P0401 - EGR Flow Insufficient Detected ; "...The EGR system is monitored during steady state driving conditions while the EGR is commanded on. The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum. Vacuum supply; EGR valve stuck closed; EGR valve leaks vacuum; EGR flow path restricted EGRVR circuit shorted to PWR VREF open to DPFE sensor; DPFE sensor downstream hose off or plugged EGRVR circuit; open to PCM VPWR open to EGRVR solenoid DPFE sensor hoses both off DPFE sensor hoses reversed Damaged EGR orifice tube Damaged EGRVR solenoid Damaged PCM Perform KOER self-test and look for DTC P1408 as an indication of a hard fault. If P1408 is not present, look for contamination, restrictions, leaks, and intermittents..."
Source: by slingblade;;
DTC P0401 EGR Flow Insufficient Detected Possible Causes; "...DTC P0401 is for exhaust gas recirculation (EGR) insufficient flow detected. This most likely means one or more of the following has happened: The EGR valve may not be opening due to a lack of vacuum; There is a blockage in the EGR (most likely carbon buildup); The DPFE sensor is faulty and needs to be replaced; The EGR valve is faulty. In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. However, just like many other DTCs, the problem is not always obvious and the EGR valve is not always the culprit..." READ MUCH MORE
Source: by Gateway Clean Air Program dnr.mo.gov
======
DTC P0171, P0172, P0174 & P0175, P1130, P1131, P1132, P1150, P1151, P1152; 181, 189 (Fuel system lean, Bank 1 or 2), 179, 188 (Fuel system rich, Bank 1 or 2); 171, 172, 173 (HO2S11 lack of switching, Bank 1); 175, 176, 177 (HO2S21 lack of switching, Bank 2); 184, 185 (MAF higher/lower than expected); 186, 187 (Injector pulse width higher/lower than expected) & Possible Causes in MAF Contamination TSB 98-23-10 for 94-96; NOTE: THE FOLLOWING PROCEDURE MAY ALSO BE USED TO DIAGNOSE VEHICLES THAT DO NOT HAVE FUEL SYSTEM/HO2S SENSOR DTCs. Symptoms: Lack of Power, Spark Knock/Detonation, Buck/**** Hesitation/Surge on Acceleration
MAF Contamination TSB 98-23-10 for 94-96
Source: by Ford via miesk5 at cc ISSUE: This TSB article is a diagnostic procedure to address vehicles that exhibit lean driveability symptoms and may or may not have any Diagnostic Trouble Codes (DTCs) stored in memory.
ACTION: Follow the diagnostic procedures described in the following Service Tip. The revised diagnostic procedure is a more accurate means of diagnosing the symptoms.
SERVICE TIP MASS AIR FLOW (MAF) DISCUSSION
MAF sensors can get contaminated from a variety of sources: dirt, oil, silicon, spider webs, potting compound from the sensor itself, etc. When a MAF sensor gets contaminated, it skews the transfer function such that the sensor over-estimates air flow at idle (causes the fuel system to go rich) and under-estimates air flow at high air flows (causes fuel system to go lean). This means Long Term Fuel Trims will learn lean (negative) corrections at idle and learn rich (positive) corrections at higher air flows.
If vehicle is driven at Wide Open Throttle (WOT) or high loads, the fuel system normally goes open loop rich to provide maximum power. If the MAF sensor is contaminated, the fuel system will actually be lean because of under-estimated air flow. During open loop fuel operation, the vehicle applies Long Term Fuel Trim corrections that have been learned during closed loop operation. These corrections are often lean corrections learned at lower air flows. This combination of under-estimated air flow and lean fuel trim corrections can result in spark knock/detonation and lack of power concerns at WOT and high loads.
One of the indicators for diagnosing this condition is barometric pressure. Barometric pressure (BARO) is inferred by the Powertrain Control Module (PCM) software at part throttle and WOT (there is no actual BARO sensor on MAF-equipped vehicles, except for the 3.8L Supercharged engine). At high air flows, a contaminated MAF sensor will under-estimate air flow coming into the engine, hence the PCM infers that the vehicle is operating at a higher altitude. The BARO reading is stored in Keep Alive Memory (KAM) after it is updated. Other indicators are Long Term Fuel Trim and MAF voltage at idle.
NOTE: THE FOLLOWING PROCEDURE MAY ALSO BE USED TO DIAGNOSE VEHICLES THAT DO NOT HAVE FUEL SYSTEM/HO2S SENSOR DTCs.
Symptoms
Lack of Power
Spark Knock/Detonation
Buck/****
Hesitation/Surge on Acceleration
Malfunction Indicator Lamp (MIL) Illuminated - DTCs P0171, P0172, P0174, P0175 may be stored in memory
OBDII DTCs
P0171, P0174 (Fuel system lean, Bank 1 or 2)
P0172, P0175 (Fuel system rich, Bank 1 or 2)
P1130, P1131, P1132, (HO2S11 lack of switching, Bank 1)
P1150, P1151, P1152, (HO2S21 lack of switching, Bank 2)
OBDI DTCs
181, 189 (Fuel system lean, Bank 1 or 2)
179, 188 (Fuel system rich, Bank 1 or 2)
171, 172, 173 (HO2S11 lack of switching, Bank 1)
175, 176, 177 (HO2S21 lack of switching, Bank 2)
184, 185 (MAF higher/lower than expected)
186, 187 (Injector pulse width higher/lower than expected)
NOTE: DO NOT DISCONNECT THE BATTERY. IT WILL ERASE KEEP ALIVE MEMORY AND RESET LONG TERM FUEL TRIM AND BARO TO THEIR STARTING/BASE VALUES. THE BARO PARAMETER IDENTIFICATION DISPLAY (PID) IS USED FOR THIS DIAGNOSTIC PROCEDURE. ALL OBDII APPLICATIONS HAVE THIS PID AVAILABLE. THERE ARE SOME OBDI VEHICLES THAT DO NOT HAVE THE BARO PID, FOR THESE VEHICLES OMIT THE BARO CHECK AND REFER ONLY TO STEPS 2, 3, AND 4 IN THE DIAGNOSTIC PROCEDURE.
1. Look at the BARO PID. Refer to the Barometric Pressure Reference Chart in this article. At sea level, BARO should read about 159 Hz (29.91 in. Hg). As a reference, Denver, Colorado at 1524 meters (5000 ft.) altitude should be about 144 Hz (24.88 in. Hg.). Normal learned BARO variability is up to ±6 Hz (±2 in. Hg.). If BARO indicates a higher altitude than you are at (7 or more Hz lower than expected), you may have MAF contamination. If available, Service Bay Diagnostic System (SBDS) has a Manifold Absolute Pressure (MAP) sensor that can be used as a barometric pressure reference. Use "MAP/BARO" test under "Powertrain," "Testers and Meters." Ignore the hookup screen. Connect GP2 to the reference MAP on the following screen.
NOTE: REMEMBER THAT MOST WEATHER SERVICES REPORT A LOCAL BAROMETRIC PRESSURE THAT HAS BEEN CORRECTED TO SEA LEVEL. THE BARO PID, ON THE OTHER HAND, REPORTS THE ACTUAL BAROMETRIC PRESSURE FOR THE ALTITUDE THE VEHICLE IS BEING OPERATED IN. LOCAL WEATHER CONDITIONS (HIGH AND LOW PRESSURE AREAS) WILL CHANGE THE LOCAL BAROMETRIC PRESSURE BY SEVERAL INCHES OF MERCURY (±3 Hz, ±1 in. Hg.).
NOTE: BARO IS UPDATED ONLY WHEN THE VEHICLE IS AT HIGH THROTTLE OPENINGS. THEREFORE, A VEHICLE WHICH IS DRIVEN DOWN FROM A HIGHER ALTITUDE MAY NOT HAVE HAD AN OPPORTUNITY TO UPDATE THE BARO VALUE IN KAM. IF YOU ARE NOT CONFIDENT THAT BARO HAS BEEN UPDATED, PERFORM THREE OR FOUR HEAVY, SUSTAINED ACCELERATIONS AT GREATER THAN HALF-THROTTLE TO ALLOW BARO TO UPDATE.
2. On a fully warmed up engine, look at Long Term Fuel Trim at idle, in Neutral, A/C off, (LONGFT1 and/or LONGFT2 PIDs). If it is more negative than -12%, the fuel system has learned lean corrections which may be due to the MAF sensor over-estimating air flow at idle. Note that both Banks 1 and 2 will exhibit negative corrections for 2-bank system. If only one bank of a 2-bank system has negative corrections, the MAF sensor is probably not contaminated.
3. On a fully warmed up engine, look at MAF voltage at idle, in Neutral, A/C off (MAF V PID). If it's 30% greater than the nominal MAF V voltage listed in the Powertrain Control/Emissions Diagnosis (PC/ED) Diagnostic Value Reference Charts for your vehicle, or greater than 1.1 volts as a rough guide, the MAF sensor is over-estimating air flow at idle.
4. If at least two of the previous three steps are true, proceed to disconnect the MAF sensor connector. This puts the vehicle into Failure Mode and Effects Management (FMEM). In FMEM mode, air flow is inferred by using rpm and throttle position instead of reading the MAF sensor. (In addition, the BARO value is reset to a base/unlearned value.) If the lean driveability symptoms go away, the MAF sensor is probably contaminated and should be replaced. If the lean driveability symptoms do not go away, go to the PC/ED Service Manual for the appropriate diagnostics.
NOTE:
DUE TO INCREASINGLY STRINGENT EMISSION/OBDII REQUIREMENTS, IT IS POSSIBLE FOR SOME VEHICLES WITH MAF SENSOR CONTAMINATION TO SET FUEL SYSTEM DTCs AND ILLUMINATE THE MIL WITH NO DRIVEABILITY CONCERNS. DISCONNECTING THE MAF ON THESE VEHICLES WILL, THEREFORE, PRODUCE NO IMPROVEMENTS IN DRIVEABILITY. IN THESE CASES, IF THE BARO, LONGFT1, LONGFT2, AND MAF V PIDs INDICATE THAT THE MAF IS CONTAMINATED, PROCEED TO REPLACE THE MAF SENSOR.
After replacing the MAF sensor, disconnect the vehicle battery (5 minutes, minimum) to reset KAM, or on newer vehicles, use the "KAM Reset" feature on the New Generation Star (NGS) Tester and verify that the lean driveability symptoms are gone.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 206000, 610000, 610500, 610600, 610700, 611000, 611500, 612000, 612500, 614000, 614500, 614600, 698298
===============
Diagnostic Trouble Code P0385 indicates a Misfire Detection Sensor Ckt Failure
Misfire Detection (MD) Sensor is located on the front of the timing chain cover, and is a two wire sensor.
Here is a pic
http://www.supermotors.org/getfile/71337/fullsize/CPS.JPG
dead in the middle of this photo - black connector
Is MD sensor disconnected?
However that code could also be generated because of a misfire. Also check for any crossfiring plug wires and make sure that the spark plugs are in good condition. The quick way to check for crossfiring plug wires is to mist the plug wires lightly with water when it is dark and watch for sparks
from 96 Bronco EVTM
The misfire sensor is an electromagnetic inductance coil similar in operation to a camshaft or crankshaft position sensor. A four-point stator, or pulse ring, located behind the crankshaft damper generates an electrical impulse in the sensor at each 90 degrees of rotation. The powertrain control module (PCM) (12A650) monitors the sensor pulses and flags any misfire events. When a specified number of misfires occur within a certain time frame, the powertrain control module will alert the driver to the condition by turning on the malfunction indicator light (MIL).
Note:
Misfire sensor is not required on 49 State/Canada 7.5L engine. It is required on a 7.5L California engine
PIN-POINT TEST
Distributor Ignition
Key On Engine Off:
Key On Engine Running:
«DK1»
Continuous Memory:
«DK1»
Diagnostic Trouble Code (DTC) P0385 indicates that Self-Test has detected a Misfire Detection (MD) Sensor circuit failure.
Possible causes:
MD circuit open.
MD circuit shorted to GND.
MD circuit shorted to PWR.
SIG RTN open
Damaged MD Sensor.
Damaged PCM.
Start engine.
Will the engine start?
Yes GO to «DK2».
http://fullsizebronco.com/forum/attachment.php?attachmentid=18087&stc=1&d=1315834507
No - DTC P0385 is not the cause of the No Start. GO to «Section 4A», Symptom Flowchart
See attachment
DK2 CLEAR AND ATTEMPT TO RE-GENERATE DTC P0385
Complete PCM Reset to clear DTCs (refer to Section 2A, «Powertrain Control Module (PCM) Reset»).
Start engine.
Increase rpm to greater than 1500 rpm for 10 seconds. Repeat two times.
Key off.
Retrieve all Continuous Memory DTCs.
Is DTC P0385 present?
Yes GO to «DK5».
No The fault that produced DTC P0385 is intermittent. GO to Pinpoint Test Step «Z50»
Z50 step should be used with the Intermittent Ignition Analyzer (Part No. Rotunda 007-00075). If this analyzer is not available, or this is a coil on plug application, return to «Z1» and choose another procedure.
DK5
Key off.
MD sensor vehicle harness connector disconnected.
Disconnect PCM. Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
*** miesk5 Note; as I mentioned in another thread here; In place of the breakout box, go to the EEC pin instead ****
BOB pins are same as PCM pins; use str8 pin to probe wires w/meter lead attached.
See PCM Connector pin diagram
http://web.archive.org/web/20130513041508im_/http://oldfuelinjection.com/images/eec05.gif
Pin Number Circuit Circuit Function
1 315 (P/O) PCM to Transmission Shift Solenoid No. 2
2 658 (P/LG) PCM to Check Engine Indicator Lamp
3 � Not Used
4 � Not Used
5 � Not Used
6 651 (BK/Y) Dedicated Ground
7 � Not Used
8 � Not Used
9 � Not Used
10 � Not Used
11 � Not Used
12 � Not Used
13 107 (P) PCM Flash EEPROM Power Supply
14 784 (LB/BK) 4x4 Low Range Switch to PCM Indicator Lamp
15 915 (PK/LB) J1850 Bus Negative/Data Negative (Return) to PCM
16 914 (T/O) J1850 Bus Positive/Data Positive
17 � Not Used
18 � Not Used
19 � Not Used
20 � Not Used
21 � Not Used
22 � Not Used
23 259 (O/R) Dedicated Ground to TFI Module
24 570 (BK/W) Dedicated Ground � PCM
25 875 (BK/LB) Ground Logic Module
26 � Not Used
27 237 (O/Y) PCM to Transmission Shift Solenoid No. 1
28 � Not Used
29 224 (T/W) Transmission Overdrive Cancel Switch to PCM
30 � Not Used
31 � Not Used
32 � Not Used
33 676 (PK/O) Vehicle Speed Sensor � Negative (Return) to PCM
34 � Not Used
35 392 (P/LG) Heated Exhaust Gas Oxygen Sensor No. 3 to PCM
36 968 (T/LB) Mass Airflow Return
37 923 (O/BK) Transmission Oil Temperature to PCM
38 354 (LG/R) Engine Coolant Temperature Sensor to PCM
39 743 (GY) Air Charge Temperature Sensor to PCM
40 238 (DG/Y) Fuel Pump Monitor to PCM/Fuel Pump Relay to Safety Switch
41 198 (DG/O) A/C Pressure Switch to Control Relay
42 � Not Used
43 � Not Used
44 200 (BR) PCM to Air Management No. 2 (Was TAD)
45 � Not Used
46 � Not Used
47 360 (BR/PK) PCM to Electronic Vacuum Regulator � Constant Current
48 382 (Y/BK) PCM to Test Connector No. 2
49 395 (GY/O) Profile Ignition Pickup to PCM
50 929 (PK) PCM to Spark Angle Pulse Width/Spark Output
51 570 (BK/W) Dedicated Ground � PCM
52 � Not Used
53 924 (BR/O) PCM to Transmission Coast Clutch Solenoid
54 480 (P/Y) PCM to Transmission Converter Clutch Control
55 37 (Y) Battery to Load
56 191 (LG/BK) PCM Top Vapor Management Valve � Constant Current
57 310 (Y/R) Knock Sensor No. 1 to PCM
58 679 (GY/BK) Vehicle Speed Sensor � Positive to PCM
59 917 (DG/LG) Misfire Detection Sensor � Feed
60 74 (GY/LB) Heated Exhaust Gas Oxygen Sensor No. 1 to PCM
61 � Not Used
62 � Not Used
63 � Not Used
64 199 (LB/Y) Manual Lever Position Sensor to PCM
65 352 (BR/LG) Delta Exhaust Pressure Transducer to PCM
66 � Not Used
67 � Not Used
68 � Not Used
69 � Not Used
70 190 (W/O) PCM to Air Management No. 1 (Was TAB)
71 361 ® Power Output from PCM Relay
72 561 (T/R) PCM to Fuel Injector No. 7 Cylinder
73 559 (T/BK) PCM to Fuel Injector No. 5 Cylinder
74 557 (W) PCM to Fuel Injector No. 3 Cylinder
75 555 (T) PCM to Fuel Injector No. 1 Cylinder or Bank No. 1
76 570 (BK/W) Dedicated Ground � PCM
77 570 (BK/W) Dedicated Ground � PCM
78 � Not Used
79 911 (W/LG) PCM to Output Circuit Indicator Lamp/Overdrive Cancel Indicator
80 926 (LG/O) PCM to Fuel Pump Relay Control
81 925 (W/Y) PCM to Electronic Pressure Control No. 1
82 � Not Used
83 264 (W/LB) PCM to Idle Speed Control Motor No. 1
84 136 (DB/Y) Output Shaft Speed to PCM
85 � Not Used
86 � Not Used
87 94 (R/BK) Heated Exhaust Gas Oxygen Sensor No. 2 to PCM
88 967 (LB/R) Mass Air Flow Sensor to PCM
89 355 (GY/W) Throttle Position Sensor to PCM/Diesel Fuel Injector Pump Lever Sensor
90 351 (BR/W) Power to Engine Sensors
91 359 (GY/R) Sensor Signal Return
92 511 (LG) Stoplamp (Brake On/Off) Switch to Stoplamps
93 387 (R/W) HEGO Sensor Heater Voltage Monitor No. 1 to PCM
94 388 (Y/LB) HEGO Sensor Heater Voltage Monitor No. 2 to PCM
95 389 (W/BK) HEGO Sensor Heater Voltage Monitor No. 3 to PCM
96 � Not Used
97 361 ® Power Output from PCM Relay
98 562 (LB) PCM to Fuel Injector No. 8 Cylinder
99 560 (LG/O) PCM to Fuel Injector No. 6 Cylinder
100 558 (BR/LB) PCM to Fuel Injector No. 4 Cylinder
101 556 (W) PCM to Fuel Injector No. 2 Cylinder or Bank No. 2
102 � Not Used
103 570 (BK/W) Dedicated Ground � PCM
104 � Not Used
Measure resistance between MD circuit at the MD vehicle harness connector and Test Pin 59 (MD) at the breakout box.
Measure resistance between misfire RTN circuit at the MD vehicle harness connector and Test Pin 6 (SIG RTN) at the breakout box.
Are resistance measurements less than 5.0 ohms?
Yes GO to «DK6».
No SERVICE open circuit. REMOVE breakout box.
RECONNECT all components. RERUN «Quick Test».
DK6 CHECK MD FOR SHORT TO POWER
Key off.
MD sensor disconnected.
Breakout box installed, PCM disconnected.
Key on, engine off.
Measure voltage between Test Pin 59 (MD) and Test Pins 51 and 103 (PWR GND) at the breakout box.
Is voltage less than 1.0 volt?
Yes GO to «DK7».
No SERVICE MD circuit for short to power. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test»
DK7 CHECK MD FOR SHORT TO GND
Key off.
Breakout box installed, PCM disconnected.
MD sensor disconnected.
Measure resistance between Test Pin 59 (MD) and Test Pins 51, 103 (PWR GND) and 6 (misfire RTN).
Is each resistance greater than 10,000 ohms?
Yes GO to «DK8».
No SERVICE MD circuit for short to GND or SIG RTN. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test»
DK8 CHECK FOR SHORTS IN PCM
Key off.
MD sensor disconnected.
Breakout box installed.
Connect PCM to breakout box.
Measure resistance between Test Pin 59 (MD) and Test Pins 51, 103 (PWR GND), 71, 97 (VPWR), and 6 (misfire RTN), and 23 (IGN GND) at the breakout box.
Is each resistance greater than 500 ohms?
Yes GO to «DK9».
No REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».
K9 CHECK MD SENSOR OUTPUT
Key off.
Breakout box installed, PCM connected.
Reconnect MD sensor.
DVOM on AC scale (to monitor less than 5.0 volts).
Measure voltage between Test Pin 59 (MD) and Test Pins 51 and 103 (PWR GND) at the breakout box while running engine at varying rpm.
Does AC voltage vary greater than 0.1 volt AC?
Yes REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».
No GO to «DK10».
K10 INSPECT MD SENSOR TRIGGER WHEEL
Is the MD sensor trigger wheel damaged, i.e., loose or misaligned?
Yes REPLACE or SERVICE as required. REMOVE all test equipment. RECONNECT all components. RERUN «Quick Test».
No REPLACE sensor. REMOVE breakout box. RECONNECT all components. RERUN «Quick Test».
.................
Removal1. Disconnect battery negative cable.
2. If engine is a V-8, proceed to next step. On a 4.9L engine, remove engine cooling fan and shroud. Refer to «Section 03-05».
3. Remove attaching screws and timing pointer.
4. Disconnect wiring and remove sensor.
Installation
1. Follow removal procedures in reverse order.
2. Tighten attaching screws to 8-12 N-m (75-105 lb-in).
--
"...The Misfire Detection Sensor is used with a TFI distributor system. The PIP signal generated by the distributor is not accurate enough to detect misfires. Because of this, a dedicated misfire detection sensor is used along with a crankshaft-mounted toothed wheel.
The following vehicles use the MFDS: 4.9L E and F-Series, 5.0L E, F-Series, and Explorer, 5.8L E, F-Series and Bronco, 7.5L E and F-Series
Misfire Detection Sensor Check
Misfire Detection Sensor Check Operation:
DTC P0385 (MFDS) Monitor execution continuous;
The LDR Misfire Monitor uses a low-data-rate crankshaft position signal, (i.e. one position reference signal at 10 deg BTDC for each cylinder event). Distributor ignition systems utilize a dedicated misfire detection sensor.
The PCM calculates crankshaft rotational velocity for each cylinder from this crankshaft position signal. The acceleration for each cylinder can then be calculated using successive velocity values. The changes in overall engine rpm are removed by subtracting the median engine acceleration over a complete engine cycle. The resulting deviant cylinder acceleration values are used in evaluating misfire in the “General Misfire Algorithm
Processing” section below.
On some vehicles, “profile correction” software is used to “learn” and correct for mechanical inaccuracies in crankshaft tooth spacing under de-fueled engine conditions (requires three 60 to 40 mph no-braking decels after Keep Alive Memory has been reset). These learned corrections improve the high-rpm capability of the monitor formost engines. The misfire monitor is not active until a profile has been learned..."
http://fullsizebronco.com/forum/attachment.php?attachmentid=18084&stc=1&d=1315828537
-------------------------
P1131 upstream oxygen sensor is not switching rich to lean and back as frequently as it should. This could be due to a vacuum leak, a failing oxygen sensor, or a rich fuel mixture.
Possible Causes are; high fuel pressure, low fuel pressure, restricted fuel filter, engine misfire, leaking intake manifold gasket, incorrect (stuck open or too cold) engine thermostat, low engine coolant level, restricted air filter, leaking vacuum hoses, or anything else that could affect fuel mixture
Source: by Ford via miesk5
======
DTC P0171 & P0174 Lean Troubleshooting; "...These codes commonly occur on many Ford vehicles, and are set when the powertrain control module (PCM) sees the air/fuel mixture is running too lean (too much air, not enough fuel). Unmetered air can enter the engine through a vacuum leak, a dirty airflow sensor (MAF) that is not reading airflow accurately, an EGR valve is not closing (DPFE) and is leaking exhaust into the intake manifold, an EGR valve that is allowing too much flow (because the EGR differential pressure sensor that monitors EGR flow is faulty and is under-reporting EGR flow). If the problem is not enough fuel, the underling cause may be a weak fuel pump, restricted fuel filter, leaky fuel pressure regulator or dirty fuel injectors..."
Source: by Larry C at AA1Car.com
DTC P0171 - System to Lean (Bank 1); "... The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The test fails when the adaptive fuel tables reach a rich calibrated limit. For lean and rich DTCs: Fuel system Excessive fuel pressure. Leaking/contaminated fuel injectors. Leaking fuel pressure regulator. Low fuel pressure or running out of fuel. Vapor recovery system. Induction system: Air leaks after the MAF. Vacuum Leaks. PCV system. Improperly seated engine oil dipstick. EGR system: Leaking gasket. Stuck EGR valve. Leaking diaphragm or EVR. Base Engine: Oil overfill. Cam timing. Cylinder compression. Exhaust leaks before or near the HO2Ss ..."
Source: by slingblade
DTC P0171, P0172, P0174 & P0175, P1130, P1131, P1132, P1150, P1151, P1152; 181, 189 (Fuel system lean, Bank 1 or 2), 179, 188 (Fuel system rich, Bank 1 or 2); 171, 172, 173 (HO2S11 lack of switching, Bank 1); 175, 176, 177 (HO2S21 lack of switching, Bank 2); 184, 185 (MAF higher/lower than expected); 186, 187 (Injector pulse width higher/lower than expected) & Possible Causes in MAF Contamination TSB 98-23-10 for 94-96; NOTE: THE FOLLOWING PROCEDURE MAY ALSO BE USED TO DIAGNOSE VEHICLES THAT DO NOT HAVE FUEL SYSTEM/HO2S SENSOR DTCs. Symptoms: Lack of Power, Spark Knock/Detonation, Buck/**** Hesitation/Surge on Acceleration
MAF Contamination TSB 98-23-10 for 94-96
Source: by Ford via miesk5 at cc ISSUE: This TSB article is a diagnostic procedure to address vehicles that exhibit lean driveability symptoms and may or may not have any Diagnostic Trouble Codes (DTCs) stored in memory.
ACTION: Follow the diagnostic procedures described in the following Service Tip. The revised diagnostic procedure is a more accurate means of diagnosing the symptoms.
SERVICE TIP MASS AIR FLOW (MAF) DISCUSSION
MAF sensors can get contaminated from a variety of sources: dirt, oil, silicon, spider webs, potting compound from the sensor itself, etc. When a MAF sensor gets contaminated, it skews the transfer function such that the sensor over-estimates air flow at idle (causes the fuel system to go rich) and under-estimates air flow at high air flows (causes fuel system to go lean). This means Long Term Fuel Trims will learn lean (negative) corrections at idle and learn rich (positive) corrections at higher air flows.
If vehicle is driven at Wide Open Throttle (WOT) or high loads, the fuel system normally goes open loop rich to provide maximum power. If the MAF sensor is contaminated, the fuel system will actually be lean because of under-estimated air flow. During open loop fuel operation, the vehicle applies Long Term Fuel Trim corrections that have been learned during closed loop operation. These corrections are often lean corrections learned at lower air flows. This combination of under-estimated air flow and lean fuel trim corrections can result in spark knock/detonation and lack of power concerns at WOT and high loads.
One of the indicators for diagnosing this condition is barometric pressure. Barometric pressure (BARO) is inferred by the Powertrain Control Module (PCM) software at part throttle and WOT (there is no actual BARO sensor on MAF-equipped vehicles, except for the 3.8L Supercharged engine). At high air flows, a contaminated MAF sensor will under-estimate air flow coming into the engine, hence the PCM infers that the vehicle is operating at a higher altitude. The BARO reading is stored in Keep Alive Memory (KAM) after it is updated. Other indicators are Long Term Fuel Trim and MAF voltage at idle.
NOTE: THE FOLLOWING PROCEDURE MAY ALSO BE USED TO DIAGNOSE VEHICLES THAT DO NOT HAVE FUEL SYSTEM/HO2S SENSOR DTCs.
Symptoms
Lack of Power
Spark Knock/Detonation
Buck/****
Hesitation/Surge on Acceleration
Malfunction Indicator Lamp (MIL) Illuminated - DTCs P0171, P0172, P0174, P0175 may be stored in memory
OBDII DTCs
P0171, P0174 (Fuel system lean, Bank 1 or 2)
P0172, P0175 (Fuel system rich, Bank 1 or 2)
P1130, P1131, P1132, (HO2S11 lack of switching, Bank 1)
P1150, P1151, P1152, (HO2S21 lack of switching, Bank 2)
OBDI DTCs
181, 189 (Fuel system lean, Bank 1 or 2)
179, 188 (Fuel system rich, Bank 1 or 2)
171, 172, 173 (HO2S11 lack of switching, Bank 1)
175, 176, 177 (HO2S21 lack of switching, Bank 2)
184, 185 (MAF higher/lower than expected)
186, 187 (Injector pulse width higher/lower than expected)
NOTE: DO NOT DISCONNECT THE BATTERY. IT WILL ERASE KEEP ALIVE MEMORY AND RESET LONG TERM FUEL TRIM AND BARO TO THEIR STARTING/BASE VALUES. THE BARO PARAMETER IDENTIFICATION DISPLAY (PID) IS USED FOR THIS DIAGNOSTIC PROCEDURE. ALL OBDII APPLICATIONS HAVE THIS PID AVAILABLE. THERE ARE SOME OBDI VEHICLES THAT DO NOT HAVE THE BARO PID, FOR THESE VEHICLES OMIT THE BARO CHECK AND REFER ONLY TO STEPS 2, 3, AND 4 IN THE DIAGNOSTIC PROCEDURE.
1. Look at the BARO PID. Refer to the Barometric Pressure Reference Chart in this article. At sea level, BARO should read about 159 Hz (29.91 in. Hg). As a reference, Denver, Colorado at 1524 meters (5000 ft.) altitude should be about 144 Hz (24.88 in. Hg.). Normal learned BARO variability is up to ±6 Hz (±2 in. Hg.). If BARO indicates a higher altitude than you are at (7 or more Hz lower than expected), you may have MAF contamination. If available, Service Bay Diagnostic System (SBDS) has a Manifold Absolute Pressure (MAP) sensor that can be used as a barometric pressure reference. Use "MAP/BARO" test under "Powertrain," "Testers and Meters." Ignore the hookup screen. Connect GP2 to the reference MAP on the following screen.
NOTE: REMEMBER THAT MOST WEATHER SERVICES REPORT A LOCAL BAROMETRIC PRESSURE THAT HAS BEEN CORRECTED TO SEA LEVEL. THE BARO PID, ON THE OTHER HAND, REPORTS THE ACTUAL BAROMETRIC PRESSURE FOR THE ALTITUDE THE VEHICLE IS BEING OPERATED IN. LOCAL WEATHER CONDITIONS (HIGH AND LOW PRESSURE AREAS) WILL CHANGE THE LOCAL BAROMETRIC PRESSURE BY SEVERAL INCHES OF MERCURY (±3 Hz, ±1 in. Hg.).
NOTE: BARO IS UPDATED ONLY WHEN THE VEHICLE IS AT HIGH THROTTLE OPENINGS. THEREFORE, A VEHICLE WHICH IS DRIVEN DOWN FROM A HIGHER ALTITUDE MAY NOT HAVE HAD AN OPPORTUNITY TO UPDATE THE BARO VALUE IN KAM. IF YOU ARE NOT CONFIDENT THAT BARO HAS BEEN UPDATED, PERFORM THREE OR FOUR HEAVY, SUSTAINED ACCELERATIONS AT GREATER THAN HALF-THROTTLE TO ALLOW BARO TO UPDATE.
2. On a fully warmed up engine, look at Long Term Fuel Trim at idle, in Neutral, A/C off, (LONGFT1 and/or LONGFT2 PIDs). If it is more negative than -12%, the fuel system has learned lean corrections which may be due to the MAF sensor over-estimating air flow at idle. Note that both Banks 1 and 2 will exhibit negative corrections for 2-bank system. If only one bank of a 2-bank system has negative corrections, the MAF sensor is probably not contaminated.
3. On a fully warmed up engine, look at MAF voltage at idle, in Neutral, A/C off (MAF V PID). If it's 30% greater than the nominal MAF V voltage listed in the Powertrain Control/Emissions Diagnosis (PC/ED) Diagnostic Value Reference Charts for your vehicle, or greater than 1.1 volts as a rough guide, the MAF sensor is over-estimating air flow at idle.
4. If at least two of the previous three steps are true, proceed to disconnect the MAF sensor connector. This puts the vehicle into Failure Mode and Effects Management (FMEM). In FMEM mode, air flow is inferred by using rpm and throttle position instead of reading the MAF sensor. (In addition, the BARO value is reset to a base/unlearned value.) If the lean driveability symptoms go away, the MAF sensor is probably contaminated and should be replaced. If the lean driveability symptoms do not go away, go to the PC/ED Service Manual for the appropriate diagnostics.
NOTE:
DUE TO INCREASINGLY STRINGENT EMISSION/OBDII REQUIREMENTS, IT IS POSSIBLE FOR SOME VEHICLES WITH MAF SENSOR CONTAMINATION TO SET FUEL SYSTEM DTCs AND ILLUMINATE THE MIL WITH NO DRIVEABILITY CONCERNS. DISCONNECTING THE MAF ON THESE VEHICLES WILL, THEREFORE, PRODUCE NO IMPROVEMENTS IN DRIVEABILITY. IN THESE CASES, IF THE BARO, LONGFT1, LONGFT2, AND MAF V PIDs INDICATE THAT THE MAF IS CONTAMINATED, PROCEED TO REPLACE THE MAF SENSOR.
After replacing the MAF sensor, disconnect the vehicle battery (5 minutes, minimum) to reset KAM, or on newer vehicles, use the "KAM Reset" feature on the New Generation Star (NGS) Tester and verify that the lean driveability symptoms are gone.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 206000, 610000, 610500, 610600, 610700, 611000, 611500, 612000, 612500, 614000, 614500, 614600, 698298
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Source: by Ford via miesk5