P0046 - TURBOCHARGER BOOST CONTROL CIRCUIT/EXCESSIVE CURRENTFor a complete wiring diagram Refer to Section 8WTheory of OperationThe Boost Pressure Servo Motor is a electrically operated DC motor designed to regulate the boost pressure output of the turbocharger. The BPSM is mounted to the side of the turbocharger assembly.
The BPSM receives 12–volt power, ground and a duty-cycle ground signal from the ECM. - When Monitored:With the ignition on and the Boost Pressure Servo Motor command off.
- Set Condition:The Boost Pressure Servo Motor reports an internal error to the ECM.
Possible Causes
INTERMITTENT DTC
TURBOCHARGER MECHANICAL PROBLEM
(Z906) GROUND CIRCUIT OPEN OR HIGH RESISTANCE
(F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
BOOST PRESSURE SERVO MOTOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)1. (F344) FUSED ASD RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCETurn the ignition off.Disconnect the Boost Pressure Servo Motor harness connector.Turn the ignition on.Using a 12 volt test light connected to ground, check the (F344) Fused ASD Relay Output circuit in the Boost Pressure Servo Motor harness connector.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 2
No- Repair the (F344) Fused ASD Relay Output circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2. (Z906) GROUND CIRCUIT OPEN OR HIGH RESISTANCETurn the ignition off.Using a 12 volt test light connected to 12 volts, check the (Z906) Ground circuit in the Boost Pressure Servo Motor harness connector.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 (Z906) Ground circuit for an open circuit or high resistance.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
3. TURBOCHARGER MECHANICAL PROBLEMEnsure the ignition is off.Inspect the Turbocharger and Boost Pressure Servo Motor linkage for damage, debri and other problems that could effect Turbocharger vane movement.Were any problems found?Yes- Repair or replace as necessary.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No- Replace the Boost Pressure Servo Motor.
- Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - STANDARD PROCEDURE)