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 10.0 volts.
Conditions for Setting the DTC
| • | EGR Feedback is less than 0.14 volt at any time. |
| • | The condition is present for longer than 20 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) 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 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. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has 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. |
Diagnostic Aids
Inspect for the following conditions:
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Poor terminal connection. |
| Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Intermittents and Poor Connections Diagnosis , and Connector Repairs Wiring Systems. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. If the harness appears to be OK, observe the sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the sensor display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems. |
| • | Inspect the PCM and the engine grounds for clean and secure connections. |
If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table:
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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. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs .
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This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
Does Desired EGR Position remain close to Actual EGR Position at all commanded positions? | -- | |||||||||
Does the scan tool indicate DTC P0405 failed this ignition? | -- | Go to Diagnostic Aids | ||||||||
4 |
Is the voltage at the specified value? | 5.0V | ||||||||
5 | Probe the EGR valve pintle position circuit at the EGR valve harness connector with a J 35616-200 test lamp connected to battery positive voltage. Is the J 35616-200 test light on? | -- | ||||||||
6 |
Is the Actual EGR Position at the specified value? | 100% | ||||||||
7 |
Was a problem found? | -- | ||||||||
8 |
Is the J 35616-200 test light on? | -- | ||||||||
9 | Probe the 5 Volt Reference A circuit with a J 35616-200 test lamp to battery positive voltage. Is the J 35616-200 test light on? | -- | ||||||||
10 |
Is the J 35616-200 test light on? | -- | ||||||||
11 |
Was a problem found? | -- | ||||||||
12 | Locate and correct the short to ground in the EGR valve pintle position circuit. Refer to Wiring Repairs . Is the action complete? | -- | -- | |||||||
13 |
Was a problem found? | -- | ||||||||
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:
Is the action complete? | -- | -- | |||||||
15 |
Was a problem found? | -- | ||||||||
16 | Locate and repair short to ground in the 5 Volt Reference A circuit. Refer to Wiring Repairs . Is the action complete? | -- | -- | |||||||
17 |
Was a problem found? | -- | ||||||||
|
Important: : The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | -- | ||||||||
19 |
Does the scan tool indicate DTC P0405 failed this ignition? | -- | System OK |
