P02E8 - Diesel Intake Air Flow Position Sensor Circuit Low

Theory of Operation

The Exhaust Gas Recirculation (EGR) Airflow Control Valve is controlled by the Powertrain Control Module (PCM) and is actuated by an electric motor. A spring internal to the actuator assembly attempts to drive the valve to the fully-open position. The electric motor works to overcome the spring force when the engine control module commands the valve to close. Position feedback from the valve is sent to the PCM to allow for closed-loop control. Discrepancy in position feedback sent to the PCM, and commanded position sent to the EGR Airflow Control Valve by more than a prescribed amount will result in failure of device rationality diagnostics. Failure to properly actuate the EGR Airflow Control Valve can result in poor engine performance. This may cause active Exhaust Aftertreatment regenerations to last longer.

When Monitored:

Ignition on.

Set Condition:

The PCM detects that the Air Intake Throttle Sensor Signal circuit is below a calibrated threshold for a calibrated amount of time.

Possible Causes

AIR INTAKE THROTTLE SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
AIR INTAKE THROTTLE SENSOR SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
EGR AIRFLOW 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. ACTIVE DTC
NOTE: If there are Mass Airflow Sensor and Turbocharger DTCs present with this DTC, repair the 12-volt Supply circuit for an open or short to ground condition.

1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Start the engine and let idle.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes
• Go To 2

No
• Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based
Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

2. CHECK THE (K672) AIR INTAKE THROTTLE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. Ignition on.
2. Disconnect the EGR Airflow Control Valve harness connector.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance between ground and the (K672) Air Intake Throttle Sensor Signal circuit at the EGR Airflow Control Valve harness connector.

Is the resistance below 10k Ohms?

Yes
• Repair the (K672) Air Intake Throttle Sensor Signal circuit for a short to ground.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Go To 3

3. CHECK THE (K672) AIR INTAKE THROTTLE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1. Measure the resistance of the (K672) Air Intake Throttle Sensor Signal circuit between the EGR Airflow
Control Valve harness connector and the PCM C1 harness connector.
Is the resistance above 5.0 Ohms?

Yes
• Repair the (K672) Air Intake Throttle Sensor Signal circuit for an open or high resistance.
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Go To 4

4. CHECK THE EGR AIRFLOW CONTROL VALVE

1. Turn the ignition off.
2. Reconnect the PCM harness connector.
3. Reconnect the EGR Airflow Control Valve harness connector.
4. Ignition on, engine not running.
5. With the scan tool, erase DTCs.
6. While monitoring the scan tool, disconnect the EGR Airflow Control Valve harness connector.
7. With the scan tool, read DTCs.
Is DTC P02E9 active?

Yes
• Replace the EGR Airflow Control Valve in accordance with the Service Information.(Refer to 25 -
Emissions Control/Exhaust Gas Recirculation, Diesel/VALVE, Exhaust Gas Recirculation (EGR) Airflow Control/Removal)
• Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Go To 5

5. POWERTRAIN CONTROL MODULE
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following
conditions:

• Proper connector installation.
• Damaged connector locks.
• Corrosion.
• Other signs of water intrusion.
• Weather seal damage (if equipped).
• Bent terminals.
• Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
• Terminals that have been pushed back into the connector cavity.
• Perform a terminal drag test on each connector terminal to verify proper terminal tension.

Repair any conditions that are found.
5. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Freeze Frame and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read PCM DTCs.
Did the DTC return?

Yes
• Replace the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control/Removal) .
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

No
• Test complete.
• Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).