P0580-SPEED CONTROL SWITCH 1 CIRCUIT LOW

For a complete wiring diagram Refer to Section 8W.

When Monitored:
With the ignition key on.
Set Condition:
Speed control switch input No.1 is below the minimum acceptable voltage at the PCM. One trip fault.

Possible Causes

(V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V397) S/C SWITCH RETURN

(V71) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN

(V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND

(V71) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND

STEERING COLUMN CONTROL MODULE

SPEED CONTROL ON/OFF SWITCH

SPEED CONTROL RESUME/ACCEL SWITCH

PCM

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

Diagnostic Test

1.SPEED CONTROL SWITCH VOLTAGE LOW

NOTE: Do not press any of the Speed Control Switch buttons.

Is the Speed Control voltage below 1.0 volt?

Yes

Go To 2

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.SPEED CONTROL SWITCHES

Does the function on the Speed Control Switches have the correct resistance value?

Yes

Go To 3

Replace the Speed Control Switch that had the incorrect resistance value.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.SPEED CONTROL ON/OFF SWITCH

Did the voltage change to above 4.8 volts?

Yes

Replace the Speed Control On/Off Switch.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 4

4.SPEED CONTROL RESUME/ACCEL SWITCH

Did the voltage change to above 4.8 volts?

Yes

Replace the Speed Control Resume/Accel Switch.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 5

5.STEERING COLUMN CONTROL MODULE

Did the S/C Switch volts change to 5.0 volts?

Yes

Replace the Clockspring.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 6

6.(V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V397) S/C SWITCH RETURN CIRCUIT

Is the resistance below 5.0 ohms?

Yes

Repair the short between the (V371) S/C Switch No.1 Signal circuit and the (V397) S/C Switch Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 7

7.(V71) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT

Is the resistance below 5.0 ohms?

Yes

Repair the short between the (V71) S/C Switch No.1 Signal circuit and the (V937) Switch Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 8

8.(V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND

Is the resistance below 100 ohms?

Yes

Repair the short to ground in the (V371) S/C Switch No.1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 9

9.(V71) S/C NO.1 SWITCH SIGNAL CIRCUIT SHORTED TO GROUND

Is the resistance below 100 ohms?

Yes

Repair the short to ground in the (V71) S/C Switch No.1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 10

10.SPEED CONTROL SWITCH VOLTAGE VALUES

SWITCH POSITION	SWITCH No.1 VOLTAGE VALUE	SWITCH No.2 VOLTAGE VALUE
NO SWITCHES PRESSED	4.31 to 4.78 volts	4.31 to 4.78 volts
ON/OFF PRESSED	0.59 to 1.13 volts	3.53 to 3.92 volts
RES/ACCEL PRESSED	3.88 to 4.17 volts	2.04 to 2.47 volts
SET PRESSED	3.16 to 3.56 volts	1.17 to 1.56 volts
COAST PRESSED	2.57 to 2.94 volts	0.77 to 1.09 volts
CANCEL PRESSED	1.59 to 1.99 volts	2.84 to 3.25 volts

Are the voltage readings out of the listed specification and is there less than a 0.2 of a volt difference between the voltmeter switch values and the scan tool switch value?

Yes

Replace the Speed Control Switch.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 11

11.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)