P0584 HIGH VOLTAGE DETECTED AT THE SPEED CONTROL VACUUM DRIVER

When Monitored and Set Condition:

When Monitored: While the engine is running and the Speed control engaged.
Set Condition: The Speed Control Vacuum commanded state is on and the feedback state is off.

POSSIBLE CAUSES

• SPEED CONTROL SERVO ASSEMBLY
• (V36) SPEED CONTROL VACUUM CIRCUIT SHORTED TO VOLTAGE
• (V36) SPEED CONTROL VACUUM CIRCUIT SHORTED TO OTHER CIRCUITS
• ECM
• CRUISE CONTROL SERVO
• INTERMITTENT CONDITION

DIAGNOSTIC PROCEDURE

1. Turn the ignition off. Disconnect the Speed control servo harness connector.
   NOTE: Check connectors - Clean/repair as necessary.
   Ignition on, engine not running. With the DRBIII®, actuate the Speed Control Vacuum Solenoid. Using a 12-volt test light connected to battery positive, check the Speed Control Vacuum Solenoid Output circuit in the Speed Control Assembly harness connector.
   NOTE: The test light must illuminate brightly.
   Compare the brightness to that of a direct connection to the battery. Does the test light cycle on and off and illuminate brightly?
   Yes --> Replace the speed control servo assembly.
   No --> Go To 2
2. Turn the ignition off. Disconnect the ECM harness connector(s).
   NOTE: Check connectors - Clean/repair as necessary.
   Measure the voltage of the Speed Control Vacuum circuit between the Speed Control Assembly harness connector and the ECM harness connector. Is the voltage above 1.0 volts?
   Yes --> Go To 3
   No --> Repair the (V36) Speed control vacuum circuit shorted to voltage.
3. Measure the resistance between the Speed Control Vacuum circuit and all other pins in the ECM connectors. Is the resistance less than 10 ohms?
   Yes --> Repair the (V36) Speed Control vacuum circuit shorted to other circuit.
   No --> Go To 4
4. Reconnect the ECM harness connectors. Ignition on, engine not running. With the DRBIII®, actuate the Speed Control Vacuum Solenoid. Using a 12-volt test light connected to battery positive, check the Speed Control Vacuum Solenoid Output circuit in the Speed Control Assembly harness connector.
   NOTE: The test light must illuminate brightly.
   Compare the brightness to that of a direct connection to the battery. Does the test light cycle on and off and illuminate brightly?
   Yes --> Go To 5
   No --> Replace and program the ECM in accordance with the Service Information.
5. Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Where any problems found?
   Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
   No --> Replace the Cruise control servo.