For 1990-2009 cars
Engine Controls Components
MAF Sensor, EVAP System, EGR Valve
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 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 volts.

### Conditions for Setting the DTC

• | EGR Feedback is less than 0.14 volts 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 and Failure Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the MIL 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

• | Poor connection at PCM or EGR Valve.

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

• | A EGR valve icing or over temperature condition could have caused this DTC to set.

### Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table:

1. Verifies that the malfunction is present.

2. 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.

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 performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Important: If DTC P1635 is set, refer to DTC P1635 5 Volt Reference Circuit first.

1. Turn ON the ignition.
2. With a scan tool, 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. Turn ON the ignition, with the engine OFF.
2. With a scan tool, review and record Fail Records.
3. Operate vehicle within Fail Records conditions.

Does the scan tool indicate this DTC failed this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Disconnect the EGR
2. Measure the voltage between the EGR pintle position sensor ground circuit and the 5 volt reference A circuit using a J 39200 Digital Multimeter.

Does the voltage measure at or near the specified value?

5V

Go to Step 5

Go to Step 9

5 | Probe the EGR valve pintle position signal circuit with a J 35616-200 Test Lamp that is connected to B+. 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.
2. With a scan tool, observe the Actual EGR Position parameter.

Does the scan tool indicate Actual EGR Position at the specified value?

100%

Go to Step 13

Go to Step 7

7 |

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 17

8 |

1. Turn OFF the ignition.
2. Disconnect the PCM.
3. Probe the EGR valve pintle position circuit using a test lamp that is connected to B+.

Does the test lamp illuminate?

--

Go to Step 12

Go to Step 15

9 | Probe the 5 volt reference A circuit using a test lamp that is connected to B+. Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 11
10 |

1. Turn OFF the ignition.
2. Disconnect the PCM.
3. Probe the 5 volt reference A circuit using a test lamp that is connected to B+.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 18

11 | Test for an open in the 5 volt reference A circuit between the PCM and the EGR valve. pair as necessary. Refer to Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 17
12 | Repair the short to ground in the EGR valve pintle position circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 19 | --
13 | Inspect for the following conditions:

1. Poor connections at the EGR valve.
2. The EGR pintle position signal circuit shorted to the EGR valve control circuit.

If a problem is found, repair as necessary. Refer to Wiring Repairs or Intermittents and Poor Connections Diagnosis and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 19

Go to Step 14

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:

• | Stuck

• | Grounded driver circuit

• | Possible faulty control module

If one of the above conditions is found, inspect the oil for possible fuel contamination.

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

Did you complete the repair?

--

Go to Step 19

--

15 | Test the EGR valve pintle position circuit for a short to the sensor ground circuit. Refer to Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 18
16 | Locate and repair short to ground in the 5 volt reference A circuit. Refer to Wiring Repairs . Did you complete the repair? | -- | Go to Step 19 | --
17 | Inspect the circuits related to the EGR valve for a poor connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 18
18 | Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | Go to Step 19 | --
19 |

1. Use the scan tool in order to clear DTCs.
2. Operate the vehicle within the Fail Record conditions.

Does the DTC reset?

--

Go to Step 2

System OK