:  Dec 17, 2007



Overview

For information on the operation of the system, refer to the relevant section in the workshop manual.

Inspection and verification

  : The following tests may involve working in close proximity to hot components. Make sure adequate protection is used. Failure to follow this instruction may result in personal injury.

  : The turbocharger can continue to rotate after the engine has stopped. Do not attempt to check the turbocharger until one minute has elapsed since the engine was switched off. Failure to follow this instruction may result in personal injury.

. Verify the customer concern.

. Visually inspect for obvious mechanical or electrical faults.

Mechanical Electrical
  • Intake air system
  • Hose(s)/hose connections
  • Turbocharger
  • General engine condition.
  • Circuit(s)
  • Turbocharger actuator
  • Engine control module (ECM)
  • Electrical connections and harnesses

. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step

. Use the approved diagnostic system or a scan tool to retrieve any diagnostic trouble codes (DTCs) before moving onto the symptom chart or DTC index.
  Make sure that all DTCs are cleared following rectification
Make sure that all DTCs are cleared following rectification

Symptom chart

Symptom Possible source Action
Poor performance
  • Low/Contaminated fuel
  • Restricted air intake system
  • General engine condition
  • ECM failure
Check the fuel level and condition. Check the air intake for restriction. Check the engine condition, compressions, etc. Check for DTCs. Refer to the warranty policy and procedures manual if an ECM is suspect.
No boost
  • Electrical connections and harnesses
  • Restricted air intake system
  • Charge air cooler restricted/leaking
  • Turbocharger actuator failure
  • Turbocharger failure
  • ECM failure
Check the electrical connections and harnesses. Check the air intake for restriction/leakage (see visual inspection). For air intake checks. Check the turbocharger actuator and circuits. Refer to the electrical guides. Check the turbocharger mechanical condition. Refer to the warranty policy and procedures manual if an ECM is suspect.
No boost/excessive noise
  • Turbocharger failure
Disconnect the turbocharger intake and outlet pipework and turn the turbocharger by hand. Any roughness indicates a fault. Check any up and down movement in the turbocharger shaft. Excessive movement indicates a fault. If in doubt, compare the suspect unit with a new turbocharger.

DTC index

:
  Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5 digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last 2 digits give extra information read by the manufacturer-approved diagnostic system).

:
  For a full list of powertrain DTCs, refer to workshop manual section 303-14 - Electronic Engine Controls.

DTC Condition Possible causes Action
P004500 Turbocharger/Supercharger Boost Control A Circuit / Open
  • Variable geometry turbocharger (VGT) actuator circuit high resistance
  • VGT actuator circuit short circuit to ground
  • VGT actuator failure
  • ECM failure
Refer to the electrical guides and check the VGT circuit. Refer to the warranty policy and procedures manual if a module is suspect.
P004600 Turbocharger/Supercharger Boost Control A Circuit Range/Performance
  • Variable geometry turbocharger (VGT) actuator circuit high resistance
  • VGT actuator circuit short circuit to ground
  • VGT actuator circuit short circuit to power
  • VGT actuator failure
  • ECM failure
Refer to the electrical guides and check the VGT circuit. Refer to the warranty policy and procedures manual if a module is suspect.
P004700 Turbocharger/Supercharger Boost Control A Circuit Low
  • Variable geometry turbocharger (VGT) actuator circuit high resistance
  • VGT actuator circuit short circuit to ground
  • VGT actuator failure
  • ECM failure
Refer to the electrical guides and check the VGT circuit. Refer to the warranty policy and procedures manual if a module is suspect.
P004800 Turbocharger/Supercharger Boost Control A Circuit High
  • Variable geometry turbocharger (VGT) actuator circuit short circuit to power
  • VGT actuator failure
  • ECM failure
Refer to the electrical guides and check the VGT circuit. Refer to the warranty policy and procedures manual if a module is suspect.
P023400 Turbocharger/Supercharger A Overboost Condition
  • Air leakage
  • Manifold absolute pressure (MAP) sensor circuit high resistance
  • MAP sensor circuit short circuit to ground
  • MAP sensor circuit short circuit to power
  • MAP sensor failure
  • Exhaust gas recirculation (EGR) fault
  • VGT actuator fault
Refer to the relevant workshop manual section. Check the MAP sensor and circuits. Refer to the electrical guides. For EGR valve tests, refer to the relevant workshop manual section. Check for DTCs indicating EGR or VGT actuator faults. Refer to the warranty policy and procedures manual if a module is suspect.
P029900 Turbocharger/Supercharger A Underboost Condition
  • Air leakage post turbocharger
  • MAP sensor circuit high resistance
  • MAP sensor circuit short circuit to ground
  • MAP sensor circuit short circuit to power
  • MAP sensor failure
  • Exhaust gas recirculation (EGR) fault
  • VGT fault
  • ECM failure
Refer to the relevant workshop manual section. Check the MAP sensor and circuits. Refer to the electrical guides. For EGR valve tests, refer to the relevant workshop manual section. Check for DTCs indicating EGR or VGT actuator faults. Refer to the warranty policy and procedures manual if a module is suspect.
P226300 Turbocharger/Supercharger Boost System Performance
  • Air leakage post turbocharger
  • Intake air temperature (IAT) sensor circuit high resistance, short circuit to ground, short circuit to power
  • Manifold absolute pressure (MAP) sensor circuit high resistance, short circuit to ground, short circuit to power
  • Mass air flow (MAF) sensor circuit high resistance, short circuit to ground, short circuit to power
  • Exhaust gas recirculation (EGR) circuit high resistance, short circuit to ground, short circuit to power
  • VGT actuator failure
  • Turbocharger vanes stuck/sticking
Check the turbocharger and linkage mechanical condition. Check the intake air system condition, rectify as necessary. Check for sensor DTCs. Check the IAT and MAP sensor circuits. Refer to the electrical guides and rectify as necessary. Using a datalogger function, check the turbocharger actuator position. Turn the ignition on, engine off and command the turbocharger actuator to 95% pulse width modulated (PWM) then to 5% pulse width modulated (PWM) and recheck the turbocharger actuator position. The value at 95% pulse width modulated (PWM) should be 80 - 95%, and at 5% pulse width modulated (PWM), 0 - 20%. If this is not the case, install a new turbocharger. Clear the DTCs and test for normal operation.