DTC 54

Code 54 "Mixture Control (M/C) Solenoid Circuit:

Wiring Diagram - Mixture Control (M/C) Solenoid Circuit:

CODE 54

MIXTURE CONTROL (M/C) SOLENOID CIRCUIT (SIGNAL VOLTAGE HIGH)

Circuit Description:

Code 54 will be set if there is constant high voltage at ECM terminal "18". A shorted solenoid or shorted CKT 411 to 12 volts would cause the solenoid to remain in the full rich position, resulting in potential ECM damage, excessive fuel consumption, and excessive exhaust odor.


Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. Checks the M/C solenoid resistance to determine if the fault is in the solenoid, ECM harness, or ECM. A normal solenoid has about 20 to 32 ohms of resistance. The ECM is equipped with a fault protected quad-driver. If the M/C solenoid is under 10 ohms, only the solenoid has to be replaced, not the ECM.


2. Checks to see if reason for high voltage to terminal "18" is a faulty ECM or a short to 12 volts in CKT 411. If the test light illuminates with both ends of harness disconnected, there is a short to 12 volts in CKT 411.