P0580-SPEED CONTROL SWITCH 1 CIRCUIT LOW
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
- Set Condition:
The PCM detects that the Speed Control signal voltage is implausible.
| Possible Causes |
| INTERMITTENT DTC |
| (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO GROUND |
| (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V937) S/C SWITCH GROUND CIRCUIT |
| (V71) S/C SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE |
| (V937) S/C SWITCH GROUND CIRCUIT OPEN OR HIGH RESISTANCE |
| CLOCKSPRING |
| SPEED CONTROL SWITCH |
| STEERING CONTROL MODULE (SCM) |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Diagnostic Test
1. DTC IS ACTIVENOTE: Refer to the following table when diagnosing speed control switch voltage DTCs.
| Switch 1 Voltage (pin A27) | Switch 2 Voltage (pin A26) | |
| On/Off - Min. | 0.5882 | 3.5294 |
| On/Off - Max. | 1.1373 | 3.9216 |
| Set - Min. | 3.1569 | 1.1765 |
| Set - Max. | 3.5686 | 1.5686 |
| Cancel - Min. | 1.5882 | 2.8431 |
| Cancel - Max. | 2.0000 | 3.2549 |
| Accel - Min. | 3.8824 | 2.0392 |
| Accel - Max. | 4.1765 | 2.4706 |
Start the engine and allow it to idle for at least 60 seconds.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
NOTE: It may be necessary to test drive the vehicle and operate the speed control in order for this DTC to set.
With a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go to2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. SPEED CONTROL SWITCH
Turn the ignition off.
Remove the Speed Control Switch in accordance with the Service Information.
Turn the ignition on.
With a scan tool, read the (V71) S/C Signal 1 voltage.
NOTE: The (V71) S/C Signal 1 voltage should be above 4.8 volts with the Speed Control Switch removed.
Is the (V71) S/C Signal 1 voltage above 4.8 volts with the Speed Control Switch removed?
Yes
- Replace the Speed Control Switch in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
No
- Go to3
3. CLOCKSPRING
Turn the ignition off.
Disconnect the Steering Control Module (SCM) C5 connector.
Turn the ignition on.
With a scan tool, read the (V71) S/C Signal 1 voltage.
NOTE: The (V71) S/C Signal 1 voltage should be above 4.8 volts with the connector disconnected.
Is the (V71) S/C Signal 1 voltage above 4.8 volts with the connector disconnected?
Yes
- Replace the Clockspring in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
No
- Go to4
4. STEERING CONTROL MODULE (SCM)
Turn the ignition off.
Disconnect the Steering Control Module (SCM) C2 connector.
Turn the ignition on.
With a scan tool, read the (V71) S/C Signal 1 voltage.
NOTE: The (V71) S/C Signal 1 voltage should be above 4.8 volts with the connector disconnected.
Is the (V71) S/C Signal 1 voltage above 4.8 volts with the connector disconnected?
Yes
- Replace the Steering Control Module (SCM) in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
No
- Go to5
5. (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Measure the resistance between ground and the (V71) S/C Signal 1 circuit in the Steering Control Module (SCM) C2 harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 6
No
- Repair the (V71) S/C Signal 1 circuit for a short to ground.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
6. (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V937) S/C SWITCH GROUND CIRCUIT
Measure the resistance between the (V71) S/C Signal 1 circuit and the (V937) S/C Switch Ground circuit in the Steering Control Module (SCM) C2 harness connector.
Is the resistance above 100 ohms?
Yes
- Go to 7
No
- Repair the (V71) S/C Signal 1 circuit for a short to the Steering Control Module (SCM) circuit.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
7. (V71) S/C SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (V71) S/C Signal 1 circuit between the Steering Control Module (SCM) C2 harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to8
No
- Repair the (V71) S/C Signal 1 circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
8. (V937) S/C SWITCH GROUND CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (V937) S/C Switch Ground circuit between the Steering Control Module (SCM) C2 harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to9
No
- Repair the (V937) S/C Switch Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
9. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Powertrain Control Module (PCM).
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 PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).
No
- Replace the Powertrain Control Module (PCM) in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDURE).