yo,
As our friend here, Fred advised...that is the usual suspect!
If it helps, but still have same issues;
DTC 15 Engine Control Module (ECM, EEC) Failure Symptoms, & other makes (part ad); DTC 15 Engine Control Module (ECM, EEC) Failure; "...Check voltage and ground at ECM connector. Voltage should be no more than 0.5 volts less than the battery voltage. Remove the ECM fuse. A digital volt ohm meter (dvom) or “Hot box” must be used to check all relays, solenoids, and injectors for short circuits. A short circuit will destroy the new ECM and will void the warranty. Check engine harnesses and connectors for corrosion and damage. Wiggle cables while car is running to see if a fault occurs. Power must always be off before beginning any work on the ECM. Symptoms of ECM Failure: No start/hard start; Engine stalling; Check engine light on; Erratic idle speeds; Rough idle / engine surging..."
Source: by CARDONE® cardone.com
Possible causes:
battery or PCM was disconnected
battery cables loose or poor connections
battery discharged
KAPWR circuit open- CHECK THE KAPWR ckt
using this 86 EVTM Diagram by Ford via Ryan M; Pin 1 gets power via Y (Yellow) Wire thru a Splice 174, then thru Fusible Link N, and then to starter Relay, and then to batty + terminal.
& more Location pics in an 85 & 89 (between the starter relay and alternator)"...the first two pics are of an 89 5.0. because of the loom i wasnt able to trace the wires...The second pic is at the starter relay to show you a fusible link wire (the green wire in my fingers you can see at the eyelet there is a black plastic block). the third pic is of my 85. i think that big block is another style fusible link ford used on older stuff (but im not sure)..."
Source: by shift1313 (Matt) at Ford Bronco Zone Forums re it is in Chris B's 86
DTCs not cleared from a previous vehicle repair
EEC
===============
DTC 15 No keep Alive Memory power;
O = KOEO test key on engine off - No keep Alive Memory power (pin 1) or bad Electronic Control Assembly (EEC, ECA Processor);
M = in memory - after separator(10) in KOEO test- Keep Alive Memory (KAM) (pin 1) was interrupted
929
by Tomco Inc. tomco-inc.com
Now going to Ryan M's info;
EEC pin 1 is KA PWR also called KAPWR – Keep Alive Power
See it @ Connector Pin Outs, Bronco & Ford Truck & Van: 4.9, 460, 5.0, 5.8; miesk5 Note, see his Connector Pin Diagram Link above)
Source: by Ryan M (Fireguy50) at
http://fordfuelinjection.com/truckpinouts.html
For the EEC Connector
Connector Pin Diagram & Overview
Source: by Fireguy50 (Ryan M) at
http://fordfuelinjection.com/?p=3
TEST:
CHECK BATTERY TERMINALS
Inspect the battery cables for loose connections, corrosion.
Are the battery terminal connections in good condition?
Yes No
KEY OFF. Battery terminals are OK. GO to REPAIR battery terminals as necessary.
CHECK KEEP ALIVE POWER (KAPWR) TO EEC
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
We're checking PIN 1
Measure voltage between KAPWR circuit at the PCM harness connector and ground.
While observing digital multimeter, grasp the EEC harness and wiggle, shake or bend a small section (really, this is Ford's Wiggle test)
Does the voltage reading indicate
less than 10.5 volts?
Yes - ISOLATE and REPAIR open circuit.
No - open in KAPWR harness circuit detected. GO to CHECK FOR REPEAT OF DTC 15
Start engine and allow it to reach operating temperature.
Run Key On Engine Off Self-Test.
Retrieve Continuous Memory DTCs.
Is DTC 15 still present?
Yes - REPLACE PCM
No - drive and re-test;
do the KOEO = Key On Engine Off portion first &
Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion
Post Codes by; KOEO and
KOER