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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Eldorado 🢒 Engine 🢒 Engine Controls - 4.6L 🢒 DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

Object Number: 602212 Size: SF
Engine Controls Component Views
MAF Sensor, EVAP Components and EGR Valve
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The powertrain control module (PCM) controls the movement of the valve using the exhaust gas recirculation (EGR) control circuit. To monitor the response of the EGR valve, the PCM uses a pintle position sensor. The PCM supplies the EGR pintle position sensor with a reference voltage and a ground. The sensor provides the PCM with a signal voltage relative to EGR valve opening. When the EGR valve is near fully open, the signal voltage is close to the reference voltage. The signal voltage is low when the PCM commands the EGR closed. The PCM checks the signal voltage to make sure that the sensor operates within the proper range. If the PCM detects an excessively low signal voltage, DTC P0405 will set.

Conditions for Running the DTC

Ignition voltage is more than 11 volts.

Conditions for Setting the DTC

The PCM detects an EGR valve pintle position sensor voltage less than 0.1 volt for at least 2 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
    • The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
    • 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 Clear DTC Information function.

Diagnostic Aids

If the condition is intermittent, refer to Intermittent Conditions .

Step

Action

Values

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

Is DTC P1635 also set?

--

Go to DTC P1635 5 Volt Reference Circuit

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  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 4

Go to Step 5

4

  1. Review and record scan tool Fail Records data.
  2. Operate the vehicle within Fail Records conditions.
  3. With a scan tool, monitor Specific DTC information for DTC P0405 until the test runs.

Does the scan tool indicate DTC P0405 failed last test?

--

Go to Step 5

Go to Diagnostic Aids

5
  1. Turn OFF the ignition.
  2. Disconnect the EGR connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the 5V reference circuit with a DMM.

Does the DMM display the specified value?

5V

Go to Step 6

Go to Step 7

6
  1. Using the appropriate jumper connections, jumper the 5 volt reference A and pintle position signal circuits in the harness connector.
  2. Observe the actual EGR position display on the scan tool.

Does the scan tool indicate an EGR position near the specified value?

100%

Go to Step 9

Go to Step 8

7
  1. Turn OFF the ignition.
  2. Disconnect the PCM connector C2. Refer to Powertrain Control Module Replacement/Programming .
  3. Test for the following conditions:
    4. • An open 5V reference circuit
    • An open EGR pintle position ground circuit
    • Poor connections at the PCM
  4. If a condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

8
  1. Turn OFF the ignition.
  2. Disconnect the PCM connectors. Refer to Powertrain Control Module Replacement/Programming .
  3. Test the EGR pintle position signal circuit for the following conditions:
    4. • An open
    • A short to ground
    • A short to EGR valve control ground, or to the EGR pintle position ground circuit
    • Poor connections at the PCM
  4. If a conditions is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

9
  1. Inspect for poor connections at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. If a condition is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

10

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

Is the action complete?

--

Go to Step 12

--

11

Important:: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 12

--

12

  1. Review and record scan tool Fail Records data.
  2. Clear DTCs.
  3. Operate the vehicle within the parameters listed in the Conditions for Running the DTC.
  4. With a scan tool, monitor Specific DTC Information for DTC P0405 until the test runs.

Does the scan tool indicate that DTC P0405 passed?

--

System OK

Go to Step 3