DTC 54

Code 54 - M/C Solenoid Voltage High To ECM:

Wiring Diagram for Code 54 - M/C Solenoid Voltage High To ECM:

CODE 54 - M/C SOLENOID VOLTAGE HIGH TO ECM


Circuit Description:

Code 54 will be set if there is constant high voltage at ECM Term. "18".

A shorted solenoid or a wiring short to 12V on circuit to ECM would cause the solenoid to remain in the full rich position, resulting in potential ECM damage, excessive fuel consumption, and excessive exhaust odor.



*** THIS PROCEDURE HAS BEEN UPDATED BY TSB #86-B-102, DATED 7/86

Some 1985-86 vehicles may experience a shorted out electric purge solenoid valveto the canister purge system. This condition may be caused by moisture enteringthe electrical portion of the canister purge solenoid valve and setting a false Code 54. If this condition is encountered and the inspection of the solenoid indicates that the replacement of the solenoid is required, replace the purge solenoid valve and install a new moisture shield P/N 14066503, which has been released to correct this condition.

The ECM may also have a failed quad driver which controls the M/C solenoid and the ECM should be checked to make sure it was not damaged if the purge solenoid was shorted.

Before the new moisture shield can be installed modifications to the purge solenoid valve bracket and moisture shield must be made.

MODIFICATION: SOLENOID VALVE
The solenoid valve bracket must be reshaped to allow the valve to fit inside the moisture shield. Hold the solenoid valve and bracket firmly and bend the bracket into an "L" shape.

MODIFICATION: MOISTURE SHIELD
The moisture shield must be modified to allow the installation of a tie strap to hold the shield to the solenoid valve. A "V" shaped slot must be cut in both sides of the shields opposite the holed tab side of shield. After the modification to the shield and solenoid bracket have been completed, install the shield on the solenoid. Install the tie stap, P/N 15501907 tightly around the solenoid shield and cut off the excess length. Make sure that the tie strap is positionedbetween the center hose port and the electrical connection to the solenoid valve.


Test Description:

1. Checks the M/C solenoid resistance to determine if the fault is in the solenoid or ECM harness/ECM. A normal solenoid has about 20 to 32 ohms of resistance.


2. Checks to see if reason for high voltage to Term. '18" is a faulty ECM or a short to 12V on that wire. If the test light illuminates with both ends of harness disconnected, there is a short to 12V in the wire.