P0048 - TURBOCHARGER BOOST CONTROL CIRCUIT HIGH





For a complete wiring diagram Refer to Section 8W



Possible Causes
INTERMITTENT DTC
(K137) BOOST PRESSURE SERVO MOTOR CONTROL CIRCUIT SHORTED TO VOLTAGE
(K137) BOOST PRESSURE SERVO MOTOR CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
BOOST PRESSURE SERVO MOTOR
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

Ignition on, engine not running.
With the scan tool, Clear DTCs in the Engine Control Module (ECM).
With the scan tool, actuate the Boost Pressure Servo Motor at 100%.
Monitor the scan tool for at least two minutes.
With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes


No

2. (K137) BOOST PRESSURE SERVO MOTOR CONTROL CIRCUIT SHORTED TO VOLTAGE



Turn the ignition off.
Disconnect the Boost Pressure Servo Motor harness connector.
Disconnect the Engine Control Module (ECM) harness connector.
Remove the ASD Relay from the TIPM.
Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay Connector.
Turn the ignition on.
Measure the voltage of the (K137) Boost Pressure Servo Motor Control circuit in the Boost Pressure Servo Motor harness connector.

Is there any voltage present?

Yes


No

3. (K137) BOOST PRESSURE SERVO MOTOR CONTROL OPEN OR HIGH RESISTANCE



Turn the ignition off.
Remove the jumper wire and install the ASD Relay
Measure the resistance of the (K137) Boost Pressure Servo Motor Control circuit between the Boost Pressure Servo Motor harness connector and the Engine Control Module (ECM) harness connector.

Is the resistance below 10.0 ohms?

Yes


No

4. BOOST PRESSURE SERVO MOTOR



Turn the ignition off.
Connect the Engine Control Module (ECM) harness connector.
Turn the ignition on.
With the scan tool, actuate the Boost Pressure Servo Motor (Boost Pressure Actuator) to 100%.
Using a 12 volt test light connected to 12 volts, check the (K137) Boost Pressure Servo Motor Control circuit in the Boost Pressure Servo Motor harness connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.


NOTE: The circuit will remain actuated by the controller for 30 seconds. Be certain the actuation is active when checking the circuit.



Is the test light illuminated and bright with the actuation at 100%?

Yes


No

5. ENGINE CONTROL MODULE (ECM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Boost Pressure Servo Motor 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.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


No