Skyhawk L4-112 1.8L VIN 0 TBI (1982)
Engine Control Module: Technical Service Bulletins
ECM - Failures Caused by Shorted Relays/Solenoids
Model Year
1983
Bulletin No.
83-141
File In Group 64A
Number
16
Date
July '83
SUBJECT:
ECM FAILURES CAUSED BY SHORTED RELAYS AND/OR SOLENOIDS
MODELS AFFECTED: 1980-1/2 - 1983 CCC AND EFI EQUIPPED VEHICLES
ECM failures on EFI equipped vehicles could be due to any shorted relay or solenoid that is controlled by the ECM, although the most likely is the TCC
solenoid.
This condition may exist if the "Check Engine" light originally came "on" when the torque converter clutch would normally have been applied. The light
would then stay on, and diagnosis would indicate a faulty ECM. When the diagnostic "test" terminal is grounded, the light may flash a Code 12, "bright"
to "dim" instead of "on" and "off".
If a shorted relay or solenoid is suspected, then check its resistance and replace if it measures under 20 ohms.
To check the TCC solenoid, the drive wheels must be raised from the floor and driven fast enough to close the transmission 3rd gear switch. If the relays
and solenoid check OK and the "Check Engine" light only goes on when the TCC applies, then check the TCC solenoid at operating temperatures. A
diode connected across the TCC solenoid may only malfunction after it has reached a high temperature.
