P0046 - Turbocharger Boost Control Circuit Performance
Theory of Operation
The Variable Geometry Turbocharger (VGT) is electronically controlled by the Electronic Turbo Actuator. The Electronic Turbo Actuator is a smart device; it communicates information with the Powertrain Control Module (PCM) over the J1939 BUS. The Electronic Turbo Actuator performs its own internal diagnostics and reports failures back to the PCM. The PCM then decodes the error message and converts it to a fault code. The PCM lights the Malfunction Indicator Lamp (MIL) after the diagnostic runs and fails in two consecutive drive cycles. The PCM will turn off the MIL immediately after this diagnostic runs and passes in four consecutive drive cycles.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
• With the engine running.
Set Conditions:
• The Electronic Turbo Actuator does not receive a valid J1939 BUS position message from the Powertrain Control Module (PCM).
Default Actions:
• The MIL will illuminate.
Possible Causes
- ELECTRONIC TURBO ACTUATOR 12 VOLT SUPPLY
- ELECTRONIC TURBO ACTUATOR RETURN
- ELECTRONIC TURBO ACTUATOR POWERTRAIN CONTROL MODULE (PCM)
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTCBased Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
Diagnostic Test
1. OTHER DTCs
1. Ignition on, engine not running.
2. With the scan tool, read DTCs. Is U010C active?
Yes
• Perform the Diagnostics for U010C first.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 2
2. POWERTRAIN CONTROL MODULE
1. Turn ignition off.
2. Disconnect the Electronic Turbo Actuator harness connector. NOTE: Check connectors - Clean/repair as necessary.
3. Ignition on, engine not running.
4. After 75 seconds, monitor the system response with the scan tool. Is U010C active?
Yes
• Go To 3
No
• Replace the Powertrain Control Module in accordance with the Service Information.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
3. INTERMITTENT CONNECTION
1. Turn ignition off.
2. Reconnect the Electronic Turbo Actuator harness connector.
3. Ignition on, engine not running.
4. After 75 seconds, monitor the system response with the scan tool. Is P0046 active?
Yes
• Go To 4
No
• Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
4. PCM CONNECTION
1. Turn ignition off.
2. Disconnect the PCM harness connector.
NOTE: Check connectors - Clean/repair as necessary. Were their any dirty or damaged terminals?
Yes
• Repair/Replace as necessary.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Go To 5
5. INTERMITTENT CONNECTION
1. Turn ignition off.
2. Reconnect the Electronic Turbo Actuator harness connector.
3. Reconnect the PCM harness connector.
4. Ignition on, engine not running.
5. After 75 seconds, monitor the system response with the scan tool.I s P0046 active?
Yes
• Replace the Electronic Turbo Actuator in accordance with the Service Information.(Refer to 09 - Engine, 6.7L Diesel/Turbocharger System/ACTUATOR, Turbocharger/Removal)
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
• Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).