P0443

SYMPTOM
P0443 EVAP PURGE SOLENOID CIRCUIT

WHEN MONITORED
The ignition on or engine running. Battery voltage greater than 10 volts.

SET CONDITION
The PCM will set a trouble code if the actual state of the solenoid does not match the intended state. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- (K52) EVAP PURGE CONTROL CIRCUIT OPEN
- (K52) EVAP PURGE SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
- (K70) EVAP PURGE SOLENOID SIGNAL CIRCUIT OPEN
- (K70) EVAP PURGE SOLENOID SIGNAL CIRCUIT SHORTED TO GROUND
- EVAP PURGE 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 the 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. EVAP PURGE SOLENOID OPERATION





Turn the ignition off.
Disconnect the EVAP Purge Solenoid harness connector. Ignition on, engine not running.
Using a 12-volt test light, jump across the (K52) EVAP Purge Solenoid Control circuit and (K70) EVAP Purge Solenoid Signal circuit in the EVAP Purge Solenoid harness connector.
With a scan tool, actuate the EVAP Purge Solenoid.
Does the test light flash on and off?
Yes>> Replace the EVAP Purge Solenoid. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 3

3. (K52) EVAP PURGE SOLENOID 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 (K52) EVAP Purge Solenoid Control circuit from the EVAP Purge Solenoid harness connector to the appropriate terminal of special tool # 8815.
Is the resistance below 5.0 ohms?
Yes>> Go To 4
No>> Repair the open in the (K52) EVAP Purge Solenoid Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

4. (K52) EVAP PURGE SOLENOID CONTROL CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (K52) EVAP Purge Solenoid Control circuit in the EVAP Purge Solenoid harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (K52) EVAP Purge Solenoid Control circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 5

5. (K70) EVAP PURGE SOLENOID SIGNAL CIRCUIT OPEN





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 (K70) EVAP Purge Solenoid Signal circuit from the EVAP Purge Solenoid harness connector to the appropriate terminal of special tool # 8815.
Is the resistance below 5.0 ohms?
Yes>> Go To 6
No>> Repair the open in the (K70) EVAP Purge Solenoid Signal circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.

6. (K70) EVAP PURGE SOLENOID SIGNAL CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (K70) EVAP Purge Solenoid Signal circuit in the EVAP Purge Solenoid harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (K70) EVAP Purge Solenoid Signal circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 7

7. 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.