P0580-S/C SWITCH 1 SIGNAL CIRCUIT VOLTAGE TOO LOW

For a complete wiring diagram, refer to the Wiring Information.

When Monitored:
With the ignition on.
Set Condition:
The S/C Signal 1 voltage is below a calibrated threshold for 0.06 second.

Possible Causes
(V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT
(V71) S/C SIGNAL 1 CIRCUIT SHORTED TO GROUND
CLOCKSPRING
STEERING WHEEL JUMPER HARNESS
SPEED CONTROL SWITCH
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. DTC IS ACTIVE

1.	Ignition on, engine not running.

2.	With the scan tool, Clear DTCs in the PCM.

3.	Start the engine and test drive the vehicle.

4.	During the test drive select each of the speed control switch positions.

5.	With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go To 2

Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

2. SPEED CONTROL SWITCH

1.	Turn the ignition off.

2.	Turn the ignition on, engine not running.

3.	Disconnect the Speed Control Switch harness connector.

4.	Measure the voltage of the (V71) S/C Signal 1 circuit at the Speed Control Switch harness connector.

Does the (V71) S/C Signal 1 circuit voltage read 5.0 Volts with the Speed Control Switch harness connector unplugged?

Yes

Replace the Speed Control Switch in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 3

3. STEERING WHEEL JUMPER HARNESS

1.	Disconnect the Clockspring C8 harness connector.

2.	Measure the voltage of the (V71) S/C Signal 1 circuit at the Clockspring terminal, not the harness connector.

Does the (V71) S/C Signal 1 circuit voltage read 5.0 Volts with the Clockspring C8 harness connector unplugged?

Yes

Replace the Steering Wheel Jumper harness in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 4

4. CLOCKSPRING

1.	Disconnect the Clockspring C2 harness connector in accordance with the service information.

2.	Measure the voltage of the (V71) S/C Signal 1 circuit at the Clockspring C2 harness connector.

Does the (V71) S/C Signal 1 circuit voltage read 5.0 Volts with the Clockspring C2 harness connector unplugged?

Yes

Replace the Clockspring in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 5

5. CHECK FOR THE (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT

1.	Turn the ignition off.

2.	Measure the resistance between the (V71) S/C Signal 1 circuit and the (V937) S/C Switch Return circuit at the Clockspring C2 harness connector.

Is the resistance above 10k Ohms?

Yes

Go To 6

Repair the short between the (V71) S/C Signal 1 circuit and the (V937) S/C Switch Return circuit in the wiring harness.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

6. CHECK THE (V71) S/C SIGNAL 1 CIRCUIT FOR A SHORT TO GROUND

1.	Measure the resistance between ground and the (V71) S/C Signal 1 circuit at the Clockspring C2 harness connector.

Is the resistance above 10k Ohms?

Yes

Go To 7

Repair the (V71) S/C Signal 1 circuit for a short to ground.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

7. POWERTRAIN CONTROL MODULE

1.	Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Powertrain Control Module.

2.	Look for any chafed, pierced, pinched, or partially broken wires.

3.	Look for broken, bent, pushed out or corroded terminals.

4.	Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace the Powertrain Control Module in accordance with the service information.
Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0580-S/C SWITCH 1 SIGNAL CIRCUIT VOLTAGE TOO LOW

Possible Causes