Operation CHARM: Car repair manuals for everyone.

Scan Tool Testing and Procedures





Note: The test sequence must be run from the beginning each time; a test cannot be repeated, and an individual component cannot be tested out of sequence.

1. DIFFERENTIAL PRESSURE REGULATOR TEST
a. Connect test harness 1315 A/1 between the differential pressure regulator and the harness plug.
b. Connect a multi-meter to the test harness. Set meter to 200 mA DC scale.
c. With the ignition OFF, insert a spare fuse into the socket on top of the fuel pump relay.
d. Switch the ignition ON.
e. After at least 4 seconds, remove the fuse from the fuel pump relay.
f. The engine warning light should display 4341
g. Close the full throttle switch to activate test.
h. Differential pressure regulator current should be 10 mA (100mA with full throttle switch open).

2. CHARCOAL CANISTER SHUT-OFF SOLENOID
a. Re-insert a spare fuse into the socket on top of the fuel pump relay.
b. After at least 4 seconds, remove the fuse from the fuel pump relay.
c. The engine warning light should display 4343
d. Close the full throttle switch to activate test
e. Charcoal canister shut-off solenoid should click ON and OFF when throttle switch is closed.

3. IDLE STABILIZER VALVE TEST
a. Re-insert a spare fuse into the socket on top of the fuel pump relay.
b. After at least 4 seconds, remove the fuse from the fuel pump relay.
c. The engine warning light should display 4431
d. Close the full throttle switch to activate test
e. The idle stabilizer valve should cycle when the throttle valve is closed

4. COLD START VALVE TEST
a. Re-insert a spare fuse into the socket on top of the fuel pump relay.
b. After at least 4 seconds, remove the fuse from the fuel pump relay.
c. The engine warning light should display 4443
d. Close the full throttle switch to activate test
e. The cold start valve should click On and OFF (for 10 seconds max.) when the throttle valve is closed.