Circuit Description
The PCM monitors the 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 detects an excessively low EGR Feedback signal voltage, DTC P0405 will set.
Conditions for Running the DTC
System voltage is greater than 10 volts.
Conditions for Setting the DTC
| • | EGR Feedback is less than 0.14 volts at any time. |
| • | The condition is present for longer than 20 seconds. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data. |
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 the scan tool. |
Diagnostic Aids
| • | Poor connection at PCM or EGR Valve. |
| Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. If the harness appears to be OK, connect a J 39200 Digital Multimeter and check circuit continuity while moving connectors and wiring harnesses related to the EGR valve. A change in the DMM display will indicate the location of the malfunction. |
| • | A EGR valve icing or over temperature condition could have caused this DTC to set. |
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table:
-
Verifies that the malfunction is present.
-
If DTC P0405 will only set under certain conditions, the malfunction may be intermittent; refer to Diagnostic Aids. If an intermittent wiring problem is not present, check for a poor connection at the PCM or the EGR valve.
-
This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
|
Important: If DTC P1635 is set, refer to DTC P1635 5 Volt Reference Circuit first.
Does Desired EGR Position remain close to Actual EGR Position at all commanded positions? | -- | |||||||||
Does the scan tool indicate this DTC failed this ignition? | -- | Go to Diagnostic Aids | ||||||||
4 |
Does the voltage measure at or near the specified value? | 5V | ||||||||
5 | Probe the EGR valve pintle position signal circuit with a J 35616-200 Test Lamp that is connected to B+. Does the test lamp illuminate? | -- | ||||||||
6 |
Does the scan tool indicate Actual EGR Position at the specified value? | 100% | ||||||||
7 |
Did you find and correct the condition? | -- | ||||||||
8 |
Does the test lamp illuminate? | -- | ||||||||
9 | Probe the 5 volt reference A circuit using a test lamp that is connected to B+. Does the test lamp illuminate? | -- | ||||||||
10 |
Does the test lamp illuminate? | -- | ||||||||
11 | Test for an open in the 5 volt reference A circuit between the PCM and the EGR valve. pair as necessary. Refer to Wiring Repairs . Did you find and correct the condition? | -- | ||||||||
12 | Repair the short to ground in the EGR valve pintle position circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |||||||
13 | Inspect for the following conditions:
If a problem is found, repair as necessary. Refer to Wiring Repairs or Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||||||||
14 |
Notice: If the EGR valve shows signs of excessive heat, inspect the exhaust
system for blockage--possibly a plugged converter--using the procedure
found on the Restricted Exhaust System Check. If the exhaust system is restricted,
repair the cause. Inspect for an open injector caused by one or more of the
following conditions:
Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Did you complete the repair? | -- | -- | |||||||
15 | Test the EGR valve pintle position circuit for a short to the sensor ground circuit. Refer to Wiring Repairs . Did you find and correct the condition? | -- | ||||||||
16 | Locate and repair short to ground in the 5 volt reference A circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | -- | |||||||
17 | Inspect the circuits related to the EGR valve for a poor connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | ||||||||
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | -- | ||||||||
19 |
Does the DTC reset? | -- | System OK |
