P2173-THROTTLE ACTUATOR CONTROL SYSTEM - HIGH AIR FLOW DETECTED
 |
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Exhaust Gas Recirculation (EGR) Air Flow Control Valve is an electrically operated throttle valve motor used to assist the EGR system function by creating a vacuum in the intake system to draw exhaust gas into the intake manifold. The Solenoid receives 12 Volts from the ASD relay and is controlled by the Powertrain Control Module (PCM). With the solenoid de-energized (off) the throttle valve is in the open (full flow) position. When the PCM energizes (grounds) the throttle motor, the throttle valve closes creating a low pressure (vacuum) in the intake system. This low pressure effect helps draw exhaust gases from the EGR Valve into the intake system.
-
When Monitored:
With the engine running, in DPF regeneration.
-
Set Condition:
The Powertrain Control Module (PCM) detects EGR Air Flow Control minimum airflow threshold is not able to be reached for 6.0 seconds.
Possible Causes |
|---|
| EGR SYSTEM LEAK |
| INTAKE SYSTEM LEAK |
| EGR AIR FLOW CONTROL VALVE |
| 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 FOR AN EGR SYSTEM LEAK
| NOTE: | Repair any other fuel system related DTCs before continuing with this diagnostic procedure. |
| 1. | Turn the ignition off. |
| 2. | Visually inspect the entire EGR System for signs of a leak. |
Were any problems found?
Yes
- Go To 2
No
- Perform the appropriate repairs.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK FOR INTAKE SYSTEM AIR LEAKS
| 1. | Remove the Crankcase Vent Heater. |
| 2. | Remove the Mass Air Flow Sensor from the Turbocharger Inlet Tube. |
| 3. | Seal off and/or plug the Turbocharger Inlet Tube where the MAF sensor was removed. |
| 4. | Connect the Evaporative Emissions Leak Detector (EELD) 8404B to the Crankcase Vent Heater port in the intake duct and begin injecting smoke into the intake system. |
| 5. | Observe all intake system components for evidence of smoke leakage. |
Is there evidence of smoke leakage?
Yes
- Repair or replace as necessary.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 3
| 1. | Turn the ignition on. |
| 2. | With the scan tool, erase DTCs in the PCM. |
| 3. | Turn the ignition off. |
| 4. | Replace the EGR Air Flow Control Valve in accordance with the service information. |
| 5. | With the scan tool, perform the Diesel Particulate Filter Regeneration procedure. |
| 6. | After this procedure is complete, turn the ignition off for 60 seconds. |
| 7. | Turn the ignition on. |
| 8. | With the scan tool, select View DTCs. |
Did this DTC return?
Yes
- Replace and program the Powertrain Control Module in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Repair complete.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).