P0499

SYMPTOM
P0499-NVLD CANISTER VENT VALVE SOLENOID CIRCUIT HIGH

WHEN MONITORED
Engine running.

SET CONDITION
The PCM detects an open in the NVLD Canister vent solenoid circuits. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- (K106) NVLD SOLENOID CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
- (K106) NVLD SOLENOID CONTROL CIRCUIT OPEN
- (Z938) GROUND CIRCUIT OPEN
- NVLD SOLENOID
- PCM

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

DIAGNOSTIC TEST
1. ACTIVE DTC





Ignition on, engine not running. With a scan tool, read DTCs.
Is the DTC active at this time?
Yes>> Go To 2
No>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5. Powertrain Verification Test - Ver 5

2. NVLD SOLENOID





Turn the ignition off. Disconnect the NVLD Assembly harness connector. Measure the resistance of the NVLD Solenoid coil.
Is the resistance between 7.5 to 8.5 ohms?
Yes>> Go To 3
No>> Replace the NVLD Assembly. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

3. (K106) NVLD SOLENOID CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE





Disconnect the PCM harness connectors.
Take this measurement with the Ignition in the off (lock) position and in the Ignition on, engine off position.
Measure the voltage on the (K106) NVLD Solenoid Control circuit in the NVLD Assembly harness connector.
Is the voltage above 1.0 volt?
Yes>> Repair the short to battery voltage in the (K106) NVLD Solenoid Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 4

4. (K106) NVLD SOLENOID CONTROL CIRCUIT OPEN





Turn the ignition off.

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 (K106) NVLD Solenoid Control circuit from the NVLD Assembly harness connector to the appropriate terminal of special tool # 8815.
Is the resistance below 5.0 ohms?
Yes>> Go To 5
No>> Repair the open in the (K106) NVLD Solenoid Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

5. (Z938) GROUND CIRCUIT OPEN





Measure the resistance between the (Z938) Ground circuit and ground.
Is the resistance below 5.0 ohms?
Yes>> Go To 6
No>> Repair the open in the (Z938) Ground circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

6. 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-5.
No>> Replace and program the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.