Circuit Description
The powertrain control module (PCM) monitors the exhaust gas recirculation (EGR) valve pintle position input to ensure that the valve responds properly to commands from the PCM and to detect a fault if the pintle position sensor circuit is open or shorted. If the PCM detect an excessively low EGR position sensor signal voltage, this DTC will set.
Conditions for Running the DTC
The system voltage is more than 11 volts.
Conditions for Setting the DTC
| • | The EGR Position sensor is less than 0.35 volts at any time. |
| • | The condition is present for more than 20 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Freeze Frame/Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records. |
| • | The PCM disables the EGR for the ignition cycle. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
|
Important: If a DTC P1635 is set diagnose that DTC first.
Does the scan tool indicate that the EGR position sensor voltage is less than the specified value? | 0.35 V | Go to Step 4 | Go to Step 3 | |
3 |
Does the DTC fail this ignition? | -- | Go to Step 4 | Go to Intermittent Conditions |
4 |
Does the scan tool indicate that the EGR position sensor is near the specified value? | 100% | Go to Step 10 | Go to Step 5 |
5 |
Does the DMM display voltage near the specified value? | 5 V | Go to Step 9 | Go to Step 6 |
6 | Test the 5-volt reference circuit of the EGR position sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 7 |
7 | Test all 5-volt reference circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 8 |
8 | With a DMM connected between the EGR position sensor 5-volt reference circuit and the EGR position sensor ground circuit, observe voltage while disconnecting all sensors, one at a time, that use a 5-volt reference signal. A change in voltage indicates the faulty component. Replace that component as necessary. Refer to the appropriate replacement procedure. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 |
9 | Test the EGR valve position signal circuit for a short to ground, high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 11 |
10 | Test the EGR valve position signal circuit for a short to the EGR solenoid high control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 12 |
11 | Inspect for poor connections at the harness connector of the PCM . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 15 | Go to Step 14 |
12 | Inspect for poor connections at the harness connector of the EGR valve . Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition | -- | Go to Step 15 | Go to Step 13 |
13 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
14 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 15 | -- |
15 |
Does the DTC run and pass? | -- | Go to Step 16 | Go to Step 2 |
16 | With a scan tool, observe the stored information in Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
