DTC P0408 [MZ-CD 1.6 (Y6)]

id0102c3831700

DTC P0408

Intake throttle valve actuator control circuit high input
DETECTION CONDITION
•  The PCM monitors that the intake throttle valve actuator driver circuit current in PCM. If the intake throttle valve actuator driver circuit current is excessive high, the PCM determines that the intake throttle valve control range/performance malfunction.
POSSIBLE CAUSE
•  Open circuit between intake throttle valve terminal C and PCM terminal 247.
•  Short to ground circuit between intake throttle valve terminal C and PCM terminal 247
•  Open circuit between intake throttle valve terminal D and PCM control relay terminal E
•  Intake throttle valve malfunction
•  Intake throttle valve stuck

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 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”.
(See INTERMITTENT CONCERN TROUBLESHOOTING [MZ-CD 1.6 (Y6)].)
4
INSPECT OPERATION OF INTAKE THROTTLE VALVE
•  Remove the air pipe (air bypass valve and intake throttle valve component) with connector connected.
•  Connect the M-MDS to DLC-2.
•  Turn the engine switch to the ON position (Engine off).
•  Access EGR_TV PID.
•  Visually inspect the intake throttle valve operation using the EGR_TV PID of simulation function.
•  Does the intake throttle valve move smoothly?
Yes
Go to Step 10.
No
Clean the air pipe (air bypass valve and intake throttle valve component), then go to the next step.
5
CLASSIFY MALFUNCTION AS INTAKE THROTTLE VALVE CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY OR INTAKE THROTTLE VALVE MALFUNCTION
•  Turn the engine switch off.
•  Disconnect the intake throttle valve connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between intake throttle valve terminal C (wiring harness-side) and body ground.
•  Is the voltage B+?
Yes
Go to the next step.
No
Go to Step 8.
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 10.
No
Go to the next step.
7
INSPECT INTAKE THROTTLE VALVE ACTUATOR CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY
•  Turn the engine switch off.
•  Disconnect the PCM connector.
•  Turn the engine switch to the ON position (Engine off).
•  Measure the voltage between PCM terminal 247 (wiring harness-side) and body ground.
•  Is the voltage B+?
Yes
Repair or replace the wiring harness between intake throttle valve terminal C (wiring harness-side) and PCM terminal 247 (wiring harness-side), then go to Step 10.
No
Go to the next step.
8
INSPECT INTAKE THROTTLE VALVE ACTUATOR
•  Inspect the intake throttle valve actuator.
•  Is the intake throttle valve normal?
Yes
Go to the next step.
No
Replace the air pipe (air bypass valve and intake throttle valve component), then go to the next step.
9
INSPECT INTAKE THROTTLE VALVE CONNECTOR FOR POOR CONNECTION
•  Disconnect the intake throttle valve connector.
•  Inspect for poor connection (such as damaged, pulled-out terminals, corrosion).
•  Is there any malfunction?
Yes
Repair or replace suspected terminal, then go to Step 10.
No
Go to the next step.
10
VERIFY THAT DTC P0408 TROUBLESHOOTING IS COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Start the engine and warm-up to normal operating temperature.
•  Retrieve the DTC using the M-MDS.
•  Is the PENDING CODE same DTC present?
Yes
Replace PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)
No
Go to the next step.
11
VERIFY AFTER REPAIR PROCEDURE
•  Perform "After Repair Procedure".
•  Is there any DTC present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZ-CD 1.6 (Y6)].)
No
Troubleshooting completed.