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 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 more than 11 volts.

### Conditions for Setting the DTC

• | EGR Feedback is less than 0.30 volt 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/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:

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

The numbers below refer to the step numbers on the diagnostic table:

1. This step verifies that the malfunction is present.

2. If DTC P0405 only sets under certain conditions, the malfunction may be intermittent. Refer to Diagnostic Aids. If an intermittent wiring problem is not present, inspect for a faulty connection at the PCM or 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 replaced, the new PCM must be programmed.

#### DTC P0405 - EGR Valve Pintle Position Circuit Low Voltage

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 |

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

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

--

Go to Step 3

Go to Step 4

3 |

1. Review and record the scan tool Fail Records data.
2. Operate the vehicle within the Fail Records conditions.
3. Use a scan tool in order to monitor the Specific DTC info for DTC P0405.

Does the scan tool indicate DTC P0405 failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Disconnect the EGR valve electrical connector.
2. Use a (DMM) in order to measure the 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 9

5 | Use a test lamp connected to battery positive voltage in order to probe the EGR valve pintle position circuit at the EGR valve harness connector. Does 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 pintle position signal circuit at the EGR valve connector.
2. Observe the Actual EGR Position on the scan tool.

Is the Actual EGR Position at the specified value?

100%

Go to Step 13

Go to Step 7

7 |

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 17

8 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Use a test lamp in order to probe between the EGR valve pintle position circuit and battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 15

9 | Use a test lamp in order to probe between the 5 volt reference A circuit and battery positive voltage. Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 11
10 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Use a test lamp in order to probe between the 5 volt reference A circuit and battery positive voltage.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 18

11 |

1. Test for an open in the 5 volt reference A circuit between the PCM and the EGR valve.
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 19

Go to Step 17

12 | Locate and correct the short to ground in the EGR valve pintle position circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 19 | --
13 | Inspect for the following conditions:

1. Any faulty terminal connections at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
2. The EGR pintle position signal circuit shorted to the EGR valve control circuit Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 14

14 | Notice: In order to prevent further damage if the EGR valve shows signs of excessive heat, check 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; one of which might be an injector which is open due to one of the following reasons:

• | Stuck

• | Grounded driver circuit

Check the oil for possible fuel contamination if a stuck open fuel injector is found.

Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement .

Did you complete the replacement?

--

Go to Step 19

--

15 | Test the EGR valve pintle position circuit for a short to the sensor ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 18
16 | Locate and repair a short to ground in the 5 volt reference A circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 19 | --
17 |

1. Inspect the circuits related to the EGR valve for a faulty terminal connection at the PCM.
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 19

Go to Step 18

18 | Important: : A replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | Go to Step 19 | --
19 |

1. Review and record the scan tool Fail Records data.
2. Clear any DTCs.
3. Operate the vehicle within the Fail Records conditions.
4. Use a scan tool in order to monitor the Specific DTC info for DTC P0405.

Does the scan tool indicate DTC P0405 failed this ignition?

--

Go to Step 2

System OK