2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

P0048-TURBOCHARGER BOOST CONTROL CIRCUIT HIGH

For a complete wiring diagram, refer to the Wiring Information.


Theory of Operation

The Boost Pressure Actuator is an electrically operated DC motor designed to regulate the boost pressure output of the Turbocharger. The Boost Pressure Actuator is mounted to the side of the Turbocharger assembly. The Boost Pressure Actuator receives 12 Volt power from the Totally Integrated Power Module (TIPM) and a duty-cycle control signal from the Powertrain Control Module (PCM). When this fault is active the EGR System, DPF Regeneration, and Boost Pressure Actuator are disabled. The engine will also experience a torque reduction.


Possible Causes

(X635) BOOST PRESSURE ACTUATOR CONTROL CIRCUIT SHORTED TO VOLTAGE
(X635) BOOST PRESSURE ACTUATOR CONTROL SHORTED TO THE (F344) FUSED ASD RELAY OUTPUT CIRCUIT
TURBOCHARGER ASSEMBLY
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).


1. DTC IS ACTIVE

1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.


Is the status Active for this DTC?

Yes


No


2. CHECK THE (X635) BOOST PRESSURE ACTUATOR CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Boost Pressure Actuator harness connector.
3. Remove the ASD Relay from the TIPM.
4. Connect a jumper wire between cavity 30 and cavity 87 of the ASD Relay connector.
5. Turn the ignition on.
6. Measure the voltage of the (X635) Boost Pressure Actuator Control circuit in the Boost Pressure Actuator harness connector.


Is there any voltage present?

Yes


No


3. CHECK THE (X635) BOOST PRESSURE ACTUATOR CONTROL FOR A SHORT TO THE (F344) FUSED ASD RELAY OUTPUT CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Disconnect the TIPM C2 harness connector.
4. Remove the jumper wire and install the ASD Relay.
5. Measure the resistance between the (X635) Boost Pressure Actuator Control circuit and the (F344) Fused ASD Relay Output circuit at the Boost Pressure Actuator harness connector.


Is the resistance above 10k Ohms?

Yes


No


4. TURBOCHARGER ASSEMBLY

1. Reconnect the Boost Pressure Actuator harness connector.
2. Reconnect the PCM C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Turn the ignition off.
6. Disconnect the Boost Pressure Actuator harness connector.
7. Connect a jumper between ground and the (X635) Boost Pressure Actuator Control circuit at the Boost Pressure Actuator harness connector.
8. Turn the ignition on.
9. With the scan tool, view DTCs.


NOTE: The scan tool should display a P0047-Turbocharger Boost Control Circuit Low DTC with the jumper in place.


Did the scan tool display the DTC as described above?

Yes


No


5. POWERTRAIN CONTROL MODULE

1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Boost Pressure Actuator 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


No