P0238-TURBO BOOST PRESSURE SENSOR CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W

When Monitored:
With the ignition on.
Set Condition:
The (K37) Boost Pressure Sensor Signal circuit voltage is above 4.85 volts for 0.5 second.

Possible Causes

INTERMITTENT DTC

(K854) BOOST PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

(K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

(K656) BOOST PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE

(K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

(K656) BOOST PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

BOOST PRESSURE SENSOR

ENGINE CONTROL MODULE (ECM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Diagnostic Test

1. DTC IS ACTIVE

NOTE: If DTC P0652 or P0653 is present with this DTC, diagnose DTCs P0652 or P0653 before diagnosing this DTC.

Ignition on, engine not running.
With the scan tool, clear DTCs in the Engine Control Module (ECM).
Monitor the scan tool for at least two minutes.
Cycle the ignition key off and on several times, leaving the ignition on for at least 10 seconds at a time.
Start the engine.
Allow the engine to reach normal operating temperature.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go To 2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

2. (K854) BOOST PRESSURE SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE

Turn the ignition off.
Disconnect the Intake Air Temp/Boost Pressure Sensor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the Main Relay.
Connect a jumper wire between cavity B7 and cavity B9 of the Main Relay Connector.
Turn the ignition on.
Measure the voltage of the (K854) Boost Pressure Sensor 5 Volt Supply circuit in the Intake Air Temp/Boost Pressure Sensor harness connector.

Is there any voltage present?

Yes

Repair the (K854) Boost Pressure Sensor 5 Volt Supply circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Go to 3

3. (K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

NOTE: The jumper wire should still be in place.

Measure the voltage of the (K37) Boost Pressure Sensor Signal circuit in the Intake Air Temp/Boost Pressure Sensor harness connector.

Is there any voltage present?

Yes

Repair the (K37) Boost Pressure Sensor Signal circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Go to 4

4. (K656) BOOST PRESSURE SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE

NOTE: The jumper wire should still be in place.

Measure the voltage of the (K656) Boost Pressure Sensor Ground circuit in the Intake Air Temp/Boost Pressure Sensor harness connector.

Is there any voltage present?

Yes

Repair the (K656) Boost Pressure Sensor Ground circuit for a short to voltage.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Go to 5

5. BOOST PRESSURE SENSOR

Turn the ignition off.
Remove the jumper wire and install the Main Relay.
Connect the Engine Control Module (ECM) harness connector.
Connect a jumper wire between the (K656) Boost Pressure Sensor Ground circuit and the (K37) Boost Pressure Sensor Signal circuit in the Intake Air Temp/Boost Pressure Sensor harness connector.
Turn the ignition on.
With the scan tool, Clear DTCs.
With the scan tool, select View DTCs.

NOTE: The scan tool should display a Boost Pressure Sensor low voltage or short to ground DTC with the jumper wire in place.

Does the scan tool display the DTC(s) as described above?

Yes

Replace the Intake Air Temp/Boost Pressure Sensor in accordance with the Service Information.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Go to 6

6. (K37) BOOST PRESSURE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Turn the ignition off.
Disconnect the Engine Control Module (ECM) harness connector.
Measure the resistance of the (K37) Boost Pressure Sensor Signal circuit between the Intake Air Temp/Boost Pressure Sensor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes

Go to 7

Repair the (K37) Boost Pressure Sensor Signal circuit for an open circuit or high resistance.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

7. (K656) BOOST PRESSURE SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Measure the resistance of the (K656) Boost Pressure Sensor Ground circuit between the Intake Air Temp/Boost Pressure Sensor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes

Go to 8

Repair the (K656) Boost Pressure Sensor Ground circuit for an open circuit or high resistance.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

8. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Boost Pressure Sensor and the Engine Control Module (ECM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.

Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)

Replace the Engine Control Module (ECM) in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)