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

### 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% less than Desired EGR position when the PCM is commanding the EGR valve opened, DTC P404 will set.

### Conditions for Running the DTC

• | EGR icing is not possible.

• | EGR is not overtemp.

• | Sensor supply to EGR is good.

• | No TP or Idle Speed sensor DTCs set.

• | Desired EGR is not 0%.

• | System Voltage is above 10 volts.

### Conditions for Setting the DTC

• | Actual EGR position is at least 15% less than Desired EGR Position.

• | The above conditions are present for longer than 20 seconds.

### Action Taken When the DTC Sets

• | The PCM will illuminate the MIL during the second consecutive trip in which the diagnostic test has been run and failed.

• | The PCM will disable EGR for the rest of the ignition cycle.

• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn the MIL OFF 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

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.

| Inspect 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 J 39200 DMM and check circuit continuity while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the malfunction.

Reviewing the Fail Records vehicle milage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set.

### Test Description

The 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. Refer to EGR Valve Replacement .

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 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | 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. Refer to 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 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?

5V

Go to Step 5

Go to Step 10

5 | Probe the EGR pintle position signal circuit at the EGR valve harness connector with a test lamp connected to B+. Is the test lamp ON? | -- | 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. Check the EGR pintle position signal circuit for an open.
4. If a problem is found, repair as necessary. Refer to Wiring Repairs .

Was a problem found?

--

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 B+.

Is the test lamp ON?

--

Go to Step 13

Go to Step 14

9 |

1. Check for poor terminal connections at the EGR valve.
2. If a problem is found, repair as necessary. Refer to Intermittents and Poor Connections Diagnosis .

Was a problem found?

--

Go to Step 17

Go to Step 12

10 |

1. Check 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.

• | Pintle position ground for an open.

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

Was a problem found?

--

Go to Step 17

Go to Step 11

11 |

1. Check 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 .

Was a problem found?

--

Go to Step 17

Go to Step 15

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

1. Check 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 .

Was a problem found?

--

Go to Step 17

Go to Step 16

15 |

1. Check 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 Intermittents and Poor Connections Diagnosis .

Was a problem found?

--

Go to Step 17

Go to Step 16

16 | Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is action complete? | -- | 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. Monitor Specific DTC info for DTC P0404 using a scan tool.

Does the scan tool indicate DTC P0404 failed this ignition?

--

Go to Step 2

System OK