TEST
ACTION
APPLICABILITY
3
Turn the ignition off.
Disconnect the S/C ON/OFF/SET switch harness connector.
Turn the ignition on.
Connect a jumper wire between the S/C Switch Signal circuit and the Sensor Ground
at the ON/OFF/SET Switch harness connector.
With the DRB, read the S/C Switch volts.
Does the DRB display below 0.5 volt?
All
Yes
→ Replace the S/C ON/OFF/SET Switch.
Perform SPEED CONTROL VERIFICATION - VER-4.
No
→ Go To 4
4
Turn the ignition off.
Disconnect the S/C ON/OFF/SET Switch harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Sensor Ground circuit.
Is the resistance below 10.0 ohms?
All
Yes
→ Replace and program the Engine Control Module in accordance
with the Service Information.
Perform SPEED CONTROL VERIFICATION - VER-4.
No
→ Repair the Sensor Ground circuit for an open.
Perform SPEED CONTROL VERIFICATION - VER-4.
5
Turn the ignition off.
Disconnect the S/C ON/OFF/SET Switch harness connector.
Disconnect the ECM harness connectors.
Turn the ignition on.
Measure the voltage of the S/C Switch Signal circuit.
Is the voltage above 1.0 volt?
All
Yes
→ Repair the S/C ON/OFF/SET Switch Signal circuit for a short to
voltage.
Perform SPEED CONTROL VERIFICATION - VER-4.
No
→ Replace and program the Engine Control Module in accordance
with the Service Information.
Perform SPEED CONTROL VERIFICATION - VER-4.
127
DRIVEABILITY - DIESEL
P0579-S/C SWITCH SIGNAL CIRCUIT SIGNAL VOLTAGE TOO HIGH —
Continued