P0585-S/C SWITCH PLAUSIBILITY BETWEEN SWITCH #1 AND #2





For a complete wiring diagram Refer to Section 8W



Possible Causes
INTERMITTENT CONDITION
(V71) S/C SIGNAL #1 CIRCUIT OPEN
(V72) S/C SIGNAL #2 CIRCUIT OPEN
(V937) S/C SWITCH GROUND OPEN
SPEED CONTROL SWITCH
ENGINE CONTROL MODULE


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)



Diagnostic Test

1. CHECK FOR ACTIVE DTC

KEY
SIGNAL 1
SIGNAL 2
LO LIMIT
HI LIMIT
LO LIMIT
HI LIMIT
RELEASED
4.49
4.56
4.49
4.56
ON-OFF
0.85
1.00
3.67
3.75
SET
3.29
3.39
1.30
1.45
RESUME-ACCEL
3.98
4.05
2.17
2.29
CANCEL
1.72
1.82
2.98
3.08


NOTE: If the ECM detects and stores a DTC, the ECM also stores the engine/vehicle operating conditions under which the DTC was set. Some of these conditions are displayed on the scan tool at the same time the DTC is displayed.


NOTE: Before erasing stored DTCs, record these conditions. Attempting to duplicate these conditions may assist when checking for an active DTC.


Turn the ignition on.
With the scan tool, erase ECM DTCs.
Test drive the vehicle and activate the Speed Control.
At some point during the test drive, press each of the S/C Switch buttons.
With the scan tool, read ECM DTCs.

Did this DTC set again?

Yes


No

2. S/C SIGNALS OPEN



Turn the ignition off.
Disconnect the S/C Switch harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the (V71) S/C Signal #1 circuit and the (V72) S/C Signal #2 circuit between the S/C Switch harness connector and the ECM harness connector.

Is the resistance below 10.0 ohms for each measurement?

Yes


No

3. (V937) S/C SWITCH GROUND OPEN



Measure the resistance of the (V937) S/C Switch Ground circuit between the S/C Switch harness connector and the ECM harness connector.

Is the resistance below 10.0 ohms?

Yes


No

4. SPEED CONTROL SWITCH

Replace the S/C Switch.
Turn the ignition on.
With the scan tool, erase ECM DTCs.
Test drive the vehicle and activate the Speed Control.
At some point during the test drive, press each of the S/C Switch buttons.
Monitor the scan tool for ECM DTCs.

Did this DTC set again?

Yes


No