Code 54 - M/C Solenoid Circuit High
Code 54 will be set if there is constant high voltage at ECM terminal "18". A short circuit to 12 volts will cause M/C solenoid to remain in full rich position, resulting in potential ECM damage, excessive fuel consumption and excessive exhaust odor.
NOTE:
The following step numbers refer to the numbers in the accompanying flow chart(s).
- This test checks the M/C solenoid resistance to determine if fault is in the solenoid, ECM harness or ECM. Normal reading for a solenoid is 20-32 ohms.
- This test checks if reason for high voltage to terminal "18" is a faulty ECM or a short to 12 volts on that wire. If test light to ground lights at M/C solenoid test lead with both ends of harness disconnected, there is a short to 12 volts in wire.