For 1990-2009 cars
Engine Controls Components
Engine Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The powertrain control module (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 the difference between actual EGR position and desired EGR Position is more than 15 percent DTC P0404 will set.

### Conditions for Running the DTC

• | The ignition is ON.

• | System voltage is between 9.0-18.0 volts.

### Conditions for Setting the DTC

• | The difference between Actual EGR and Desired EGR Position is more than 15 percent.

• | 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/Failure Records data.

### 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:

Excessive deposits on the EGR pintle or seat-- Remove the EGR valve and inspect for deposits that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

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.

• | Loose terminal connection

- | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

- | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

• | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

• | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

### Test Description

Numbers below refer to the step numbers on the Diagnostic Table:

1. Verifies that the malfunction is present.

2. 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. If the connections are OK and DTC P0404 continues to set, replace the EGR valve.

3. 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.

#### DTC P0404 - EGR Valve Stuck Closed

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Important: : If any of the following DTCs are set, diagnose the other DTC first.

• | DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit

• | DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

1. Turn ON the ignition switch.
2. Select the scan tool EGR valve output control function.
3. Increment the EGR valve through all positions while comparing Desired EGR Position to Actual EGR Position.

Does Desired EGR Position remain close to Actual EGR Position at all commanded positions?

--

Go to Step 3

Go to Step 4

3 |

1. Review and record scan tool Fail Records data.
2. Operate the vehicle within Fail Records conditions.
3. Using a scan tool, monitor Specific DTC info for DTC P0404.

Does the scan tool indicate DTC P0404 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Disconnect the EGR valve.
2. Connect a J 39200 DMM to measure voltage between the EGR pintle position sensor ground circuit and the 5 volt reference A circuit at the EGR valve connector.

Is the voltage at the specified value?

5.0 V

Go to Step 5

Go to Step 10

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. Did the test lamp illuminate? | -- | Go to Step 8 | Go to Step 6
6 |

1. Connect a jumper between the 5 volt reference A circuit and the EGR pintle position signal circuit at the EGR valve connector.
2. Observe Actual EGR Position on the scan tool.

Is Actual EGR position at the specified value?

100%

Go to Step 9

Go to Step 7

7 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Test the EGR pintle position signal circuit for an open. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

8 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Probe the EGR pintle position signal circuit with a test lamp to battery positive voltage.

Did the test lamp illuminate?

--

Go to Step 13

Go to Step 14

9 | Test for poor terminal connections at the EGR valve. Refer to Testing for Continuity and Testing for Intermittent Conditions and Poor Connections in Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 12
10 |

1. Inspect for the following conditions:

• | 5 volt reference A circuit open between the PCM and the EGR valve

• | 5 volt reference A circuit shorted to ground

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 11

11 |

1. Inspect for the following conditions:

• | EGR pintle position sensor ground circuit open

• | EGR pintle position sensor ground circuit shorted to voltage

2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

12 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Did you complete the replacement? | -- | Go to Step 17 | --
13 | Locate and correct the short to ground in the EGR pintle position signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | --
14 |

1. Test the EGR pintle position signal circuit for a short to the EGR pintle position sensor ground circuit.
2. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

15 |

1. Test the circuits related to the EGR valve for poor terminal connections at the PCM.
2. If a problem is found, repair as necessary. Refer to Testing for Continuity and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

16 | Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | Go to Step 17 | --
17 |

1. Review and record scan tool Fail Records data.
2. Clear DTCs.
3. Operate the vehicle within Fail Records conditions.
4. Using a scan tool, monitor Specific DTC info for DTC P0404.

Does the scan tool indicate DTC P0404 failed this ignition?

--

Go to Step 2

System OK