Circuit Description
The PCM monitors the EGR valve pintle position input to ensure that the valve responds properly to commands from the PCM. The PCM compares Actual EGR Position with Desired EGR Position when the valve is commanded open. If Actual EGR Position is 15% different than Desired EGR position when the PCM is commanding the EGR valve opened, DTC P0404 will set.
Conditions for Running the DTC
System Voltage is between 10.0 volts and 18.0 volts.
Conditions for Setting the DTC
| • | Actual EGR position is 15% different than Desired EGR Position. |
| • | 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
Check for the following condition(s):
| • | Excessive deposits on the EGR Pintle or seat. |
| • | Remove the EGR valve and check for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick. |
| • | Poor connection at PCM or EGR Valve. |
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.
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If DTC P0404 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 Connector Repairs . If the connections are OK and DTC P0404 continues to set, replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement .
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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 OBD System Check performed? | -- | ||||||
|
Important: : If any of the following DTCs are set, diagnose the other DTC first.
Does Desired EGR Position remain close to Actual EGR Position at all commanded positions? | -- | |||||||
Does the scan tool indicate DTC P0404 failed this ignition? | -- | Go to Diagnostic Aids | ||||||
4 |
Is the voltage at the specified value? | 5.0V | ||||||
5 | Probe the EGR pintle position signal 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 Actual EGR Position at the specified value? | 100% | ||||||
7 |
Was a problem found? | -- | ||||||
8 |
Is the J 35616-200 test light on? | -- | ||||||
9 |
Was a problem found? | -- | ||||||
10 |
Was a problem found? | -- | ||||||
11 |
Was a problem found? | -- | ||||||
12 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Is the action complete? | -- | -- | |||||
13 | Locate and correct the short to ground in the EGR pintle position signal circuit. Refer to Wiring Repairs . Is the action complete? | -- | -- | |||||
14 |
Was a problem found? | -- | ||||||
15 |
Was a problem found? | -- | ||||||
|
Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | ||||||
17 |
Does the scan tool indicate DTC P0404 failed this ignition? | -- | System OK |
