P0586

SYMPTOM
P0586-SPEED CONTROL VENT CONTROL CIRCUIT

WHEN MONITORED
Engine running and the speed control switched on.

SET CONDITION
The PCM detects an open or short to voltage in the Speed Control Vent Control circuit. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- (V35) S/C VENT SOL CONTROL CIRCUIT OPEN
- (V35) S/C VENT SOL CONTROL CIRCUIT SHORTED TO GROUND
- SPEED CONTROL VENT SOLENOID
- PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Scan Tool Testing and Procedures

DIAGNOSTIC TEST
1. SPEED CONTROL VENT CONTROL





Note: If this code is setting on a vehicle that doesn't have a S/C Servo, flash the correct code into the PCM or the wrong PCM may have previously been installed.

Ignition on, engine not running.
With the scan tool, actuate the Speed Control Vent Solenoid and note operation.
Does the Speed Control Vent Solenoid actuate properly?
Yes>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4. Powertrain Verification Test - Ver 4
No>> Go To 2

2. SPEED CONTROL VENT SOLENOID





Turn the ignition off.
Disconnect the Speed Control Servo harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Speed Control Vent Solenoid.
Using a 12-volt test light connected to ground, probe the (V35) S/C Vent Solenoid Control circuit in the Speed Control Servo harness connector.
Does the test light illuminate brightly and flash?
Yes>> Replace the Speed Control Servo. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4.
No>> Go To 3

3. (V35) VENT CONTROL CIRCUIT OPEN





Turn the ignition off. Disconnect the PCM harness connectors.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool # 8815 to perform diagnosis.

Measure the resistance of the (V35) S/C Vent Control circuit from the Speed Control Servo harness connector to the appropriate terminal of special tool # 8815.
Is the resistance below 5.0 ohms?
Yes>> Go To 4
No>> Repair the excessive resistance in the (V35) S/C Vent Sol Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4.

4. (V35) VENT SOL CONTROL CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (V35) S/C Vent Solenoid Control circuit in the Speed Control Servo harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (V35) S/C Vent Sol Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4.
No>> Go To 5

5. PCM

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

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes>> Repair as necessary. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4.
No>> Replace and program the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-4.