P0585-SPEED CONTROL SWITCH 1/2 CORRELATION
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on and no other S/C Switch DTCs present.
- Set Condition:
The (V71) S/C Switch 1 Signal and (V72) S/C Switch 2 Signal do not indicate the same S/C Switch position for 5.0 seconds.
| Possible Causes |
| INTERMITTENT DTC |
| (V71) S/C SWITCH 1 SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (V72) S/C SWITCH 2 SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (V937) S/C SWITCH GROUND CIRCUIT SHORTED TO VOLTAGE |
| (V71) S/C SWITCH 1 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| (V72) S/C SWITCH 2 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| (V937) S/C SWITCH GROUND CIRCUIT OPEN OR HIGH RESISTANCE |
| (V71) S/C SWITCH 1 SIGNAL CIRCUIT SHORTED TO GROUND |
| (V72) S/C SWITCH 2 SIGNAL CIRCUIT SHORTED TO GROUND |
| SPEED CONTROL SWITCH |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Diagnostic Test
1. S/C SWITCH VOLTAGES OUT OF RANGE| KEY | SIGNAL 1 | SIGNAL 2 | ||
| LO LIMIT | HI LIMIT | LO LIMIT | HI LIMIT | |
| RELEASED | 4.36 | 4.69 | 4.36 | 4.69 |
| ON-OFF | 0.50 | 1.10 | 3.53 | 3.90 |
| SET | 3.16 | 3.53 | 1.56 | 1.18 |
| RESUME-ACCEL | 3.84 | 4.19 | 1.70 | 2.43 |
| CANCEL | 1.59 | 1.97 | 2.43 | 3.22 |
Turn the ignition on.
With the scan tool, monitor the S/C Switch signal voltages.
Press each button while noting the voltage readings for each circuit.
Do the S/C Switch voltages fall within the ranges specified in the table when each button is pressed?
Yes
Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To2
2. SPEED CONTROL SWITCH CIRCUIT OPEN OR HIGH RESISTANCE
Turn the ignition off.
Disconnect the Speed Control Switch harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance of the (V71) S/C Switch 1 Signal circuit between the Speed Control Switch harness connector and the Engine Control Module (ECM) harness connector.
Measure the resistance of the (V72) S/C Switch 2 Signal circuit between the Speed Control Switch harness connector and the Engine Control Module (ECM) harness connector.
Measure the resistance of the (V937) S/C Switch Ground circuit between the Speed Control Switch harness connector and the Engine Control Module (ECM) harness connector.
Is the resistance below 10.0 ohms for ALL measurements?
Yes
- Go To3
No
- Repair the Speed Control Switch circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
3. SPEED CONTROL SWITCH CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Remove the Main Relay.
Connect a jumper wire between cavity B7 and cavity B9 of the Main Relay connector.
Turn the ignition on.
Measure the voltage of the (V71) S/C Switch 1 Signal circuit.
Measure the voltage of the (V72) S/C Switch 2 Signal circuit.
Measure the voltage of the (V937) S/C Switch Ground circuit.
Is there any voltage present on any of the circuits?
Yes
- Repair the Speed Control Switch circuit for a short to voltage.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 4
4. SPEED CONTROL SWITCH CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Measure the resistance between ground and the (V71) S/C Switch 1 Signal circuit.
Measure the resistance between ground and the (V72) S/C Switch 2 Signal circuit.
Is the resistance above 1000 ohms?
Yes
- Go to 5
No
- Repair the Speed Control Switch circuit for a short to ground.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
5. SPEED CONTROL SWITCHES
Turn the ignition off.
Connect the Engine Control Module (ECM) harness connector.
Turn the ignition on.
With the scan tool, monitor the S/C Switch Voltage.
While monitoring the scan tool, connect a jumper wire between the (V71) S/C Switch 1 Signal circuit and the (V937) S/C Switch Ground circuit in the S/C Switch harness connector.
While monitoring the scan tool, connect a jumper wire between the (V72) S/C Switch 2 Signal circuit and the (V937) S/C Switch Ground circuit in the S/C Switch harness connector.
Does the scan tool display below 0.1 volt for each circuit with the jumper wire in place?
Yes
- Replace the Speed Control Switches in accordance with the Service Information.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go to 6
6. ENGINE CONTROL MODULE (ECM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Replace the Engine Control Module (ECM) in accordance with the Service Information.
- Perform the ECM Verification Test Ver.1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)