P0034
P0034-TURBOCHARGER SURGE VALVE CONTROL CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information
Theory of Operation
When the accelerator is closed suddenly, excessive boost pressure can build up between the Turbocharger and the Throttle Body which can cause damage to the Turbocharger. This can occur because the compressed air created by the Turbocharger has no place to go. This results in compressor surge. The Powertrain Control Module (PCM) detects this pressure increase via input from the Boost Pressure Sensor. The Boost Pressure Sensor operates as a typical three wire sensor. The PCM provides a 5-volt supply and sensor return circuit to the Boost Pressure Sensor and receives a feedback voltage on the signal circuit. The Turbocharger Surge Valve is responsible for venting the boost pressure between the Turbocharger and Throttle Body during sudden deceleration. The Turbocharger Surge Valve is normally spring loaded closed. When the PCM receives an input signal from the Boost Pressure Sensor that the pressure is above a calibrated amount, the PCM grounds the Turbocharger Surge Valve Control circuit which electrically opens the valve and routes the excess pressure between the Turbocharger and the Throttle Body back to the inlet of the Turbocharger, relieving the pressure and preventing compressor surge.
- When Monitored:
With the ignition on and the Turbocharger Surge Valve commanded closed.
- Set Condition:
The Powertrain Control Module (PCM) detects that the (K150) Turbocharger Surge Valve control circuit is less than 1.8 volts for 1.5 seconds. One trip fault. Three good trips to turn off the MIL.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure
Diagnostic Test
1. DTC IS ACTIVE
NOTE: Diagnose any system voltage DTCs first if present.
1. Ignition on, engine not running.
2. With the scan tool, clear DTCs in the Powertrain Control Module (PCM).
3. With the scan tool, actuate the Turbocharger Surge Valve to 100%.
4. Monitor the scan tool for at least two minutes.
5. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. Intermittent Condition Test.
2. (F344) FUSED MAIN RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Turbocharger Surge Valve harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, probe the (F344) Fused Main Relay Output circuits in the Turbocharger Surge Valve harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 3
No
- Repair the (F344) Fused Main Relay Output circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. (K150) TURBOCHARGER SURGE VALVE CONTROL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module C2 harness connector.
3. Measure the resistance between ground and the (K150) Turbocharger Surge Valve Control circuit in the Turbocharger Surge Valve harness connector.
Is the resistance above 10k Ohms?
Yes
- Go To 4
No
- Repair the (K150) Turbocharger Surge Valve Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. (K150) TURBOCHARGER SURGE VALVE CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K150) Turbocharger Surge Valve Control circuit between the Turbocharger Surge Valve harness connector and the PCM C2 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K150) Turbocharger Surge Valve Control circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
5. TURBOCHARGER SURGE VALVE
1. Reconnect the Powertrain Control Module harness connector.
2. Turn the ignition on.
3. With the scan tool, actuate the Turbocharger Surge Valve to 100%.
4. Using a 12-volt test light connected to 12 volts, probe the (K150) Turbocharger Surge Valve Control circuit in Turbocharger Surge Valve harness connector.
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
NOTE: Be certain the actuation is active when checking the circuit.
5. With the scan tool, actuate the Turbocharger Surge Valve to 0%.
6. Using a 12-volt test light connected to 12 Volts, probe the (K150) Turbocharger Surge Valve Control circuit in the Turbocharger Surge Valve harness connector.
NOTE: The test light should not be illuminated.
Is the test light illuminated and bright with the actuation at 100% and not illuminated with the actuation at 0%?
Yes
- Replace the Turbocharger Surge Valve.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. POWERTRAIN CONTROL MODULE
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Turbocharger Surge Valve Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.