Fuel Evap Purge Solenoid Valve - Inoperative
NUMBER: 86-B-102GROUP: 6E - Emission Controls
DATE: July, 1986
SUBJECT: SHORTED OUT ELECTRIC CANISTER PURGE SOLENOID VALVE AND A FALSE CODE 54
MODELS: 1985-86 G VANS WITH 4.3L, 5.0L, 5.7L ENGINES AND NB2 CALIFORNIA EMISSIONS
FIGURE 1 - ELECTRIC PURGE SOLENOID VALVE:
Some 1985, 86 G Vans with NB2 California emissions may experience a shorted out electric purge solenoid valve (see Figure No. 1). This condition may be caused by moisture entering tile 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 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 electronic control module (ECM) may also have a failed quad driver in the mixture control solenoid (M/C) circuit and the ECM should be checked to make sure it was not damaged if the purge solenoid valve is shorted out. If the ECM is damaged, it also must be replaced. Removal and installation procedures for the electric canister purge solenoid valve and the ECM are in Section 6E8, Emissions, of the Light Duty Service Manual. Before the new moisture shield can be installed, modifications to the purge solenoid valve bracket and moisture shield must be completed.
FIGURE 2 - RESHAPE SOLENOID VALVE BRACKET:
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" shaped form (see Figure No. 2).
FIGURE 3 - MODIFICATION OF MOISTURE SHIELD:
FIGURE 4 - TIE STRAP INSTALLATION:
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 shield opposite the holed tab side of the shield (see Figure No. 3). After the modification to the shield and solenoid bracket have been completed, install the shield on the solenoid. Install the tie strap, P/N 15501907, tightly around the solenoid and shield (see Figure No. 4) and cut off the excess length. Make sure that the tie strap is positioned between the center hose port and the electrical connection to the solenoid valve.