2012 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

P0046-TURBOCHARGER BOOST CONTROL CIRCUIT/EXCESSIVE CURRENT

P0046-TURBOCHARGER BOOST CONTROL CIRCUIT/EXCESSIVE CURRENT

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 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

(Z904) GROUND CIRCUIT OPEN/HIGH RESISTANCE
(F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN/HIGH RESISTANCE
TURBOCHARGER MECHANICAL PROBLEM
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. CHECK THE (F344) FUSED ASD RELAY OUTPUT CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Boost Pressure Actuator harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (F344) Fused ASD Relay Output circuit in the Boost Pressure Actuator 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


No


2. CHECK THE (Z904) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12 Volts, check the (Z904) Ground circuit in the Boost Pressure Actuator 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


No


3. TURBOCHARGER AND BOOST PRESSURE ACTUATOR LINKAGE

1. Make sure the ignition is off and the engine is cold.
2. Inspect the Turbocharger and Boost Pressure Actuator linkage for damage, debris and other problems that could effect Turbocharger vane movement.
3. Start engine and listen for abnormal Turbo noises.


Were any problems found?

Yes


No


4. TURBOCHARGER ASSEMBLY

1. Turn the ignition off.
2. Replace the Turbocharger Assembly and reconnect the Boost Pressure Actuator harness connector.
3. Reconnect the PCM C1 harness connector.
4. Turn the ignition on.
5. With the scan tool, erase DTCs.
6. Start the engine and allow it to idle.
7. With the scan tool, view DTCs.


Did the DTC return?

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