DTC P0406 [MZ-CD 1.6 (Y6)]


id0102c3820700

DTC P0406

EGR valve position sensor circuit high input

DETECTION CONDITION
•  The PCM monitors the EGR valve position sensor signal. If the voltage at PCM terminal 129 remains high, the PCM determines that there is a EGR valve position sensor circuit problem.
POSSIBLE CAUSE
•  EGR valve position sensor malfunction
•  Connector or terminal malfunction
•  Short to power supply in wiring harness between EGR valve position sensor terminal B and PCM terminal 129
•  Open circuit in wiring harness between EGR valve position sensor terminal A and PCM terminal 121
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has the FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
•  Verify related service repair information availability.
•  Is any related repair information available?
Yes
Perform repair or diagnosis according to the available repair information.
•  If the vehicle is not repaired, go to the next step.
No
Go to the next step.
3
VERIFY CURRENT SIGNAL STATUS: IS CONCERN INTERMITTENT OR CONSTANT?
•  Connect the M-MDS to the DLC-2.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists.
Perform the “INTERMITTENT CONCERNS TROUBLESHOOTING”.
4
CLASSIFY MALFUNCTION AS EGR VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO POWER SUPPLY OR OTHER MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the EGR valve position sensor connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between EGR valve position sensor terminal E (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Go to the next step.
No
Go to Step 7.
5
INSPECT EGR VALVE POSITION SENSOR POWER CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch off.
•  Disconnect the EGR valve position sensor connector and the PCM connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between PCM terminal 201 (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Repair or replace the wiring harness between EGR valve position sensor terminal E (wiring harness-side) and PCM terminal 201 (wiring harness-side), then go to Step 15.
No
Go to the next step.
6
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 15.
No
Go to Step 15.
7
CLASSIFY MALFUNCTION AS EGR VALVE POSITION SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY OR OTHER MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the EGR valve position sensor connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between EGR valve position sensor terminal B (wiring harness-side) and body ground.
•  Is the voltage more than 5.0 V?
Yes
Go to the next step.
No
Go to Step 10.
8
INSPECT EGR VALVE POSITION SENSOR SIGNAL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch off.
•  Disconnect the EGR valve position sensor connector and the PCM connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between PCM terminal 129 (wiring harness-side) and body ground.
•  Is the voltage more than 5V?
Yes
Repair or replace the wiring harness between EGR valve position sensor terminal B (wiring harness-side) and PCM terminal 129 (wiring harness-side), then go to Step 15.
No
Go to the next step.
9
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 15.
No
Go to Step 15.
10
CLASSIFY MALFUNCTION AS EGR VALVE POSITION SENSOR GROUND CIRCUIT FOR OPEN OR EGR VALVE POSITION SENSOR MALFUNCTION
•  Turn the engine switch off.
•  Inspect for continuity between EGR valve position sensor terminal A (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Go to Step 13.
No
Go to the next step.
11
INSPECT EGR VALVE POSITION SENSOR GROUND CIRCUIT FOR OPEN
•  Turn the engine switch off.
•  Inspect for continuity between PCM terminal 121 (wiring harness-side) and body ground.
•  Is there continuity?
Yes
Repair or replace the wiring harness between EGR valve position sensor terminal A (wiring harness-side) and PCM terminal 121 (wiring harness-side), then go to Step 15.
No
Go to the next step.
12
INSPECT PCM CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 15.
No
Go to Step 15.
13
INSPECT EGR VALVE POSITION SENSOR CONNECTOR FOR POOR CONNECTION
•  Turn the engine switch off.
•  Disconnect the EGR valve position sensor connector.
•  Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
•  Is there any malfunction?
Yes
Repair or replace the terminal, then go to Step 15.
No
Go to the next step.
14
INSPECT EGR VALVE POSITION SENSOR
•  Inspect the EGR valve position sensor.
•  Is there any malfunction?
Yes
Replace the EGR valve position sensor, then go to the next step.
No
Go to the next step.
15
VERIFY THAT DTC P0406 TROUBLESHOOTING IS COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Run the vehicle under the FREEZE FRAME DATA stored condition.
•  Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
16
VERIFY AFTER REPAIR PROCEDURE
•  Perform the after repair procedure.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.