Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Work Procedure
- INSPECTION START
- Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
- Open engine hood and check the following:
- Harness connectors for improper connections
- Wiring harness for improper connections, pinches and cut
- Vacuum hoses for splits, kinks and improper connections
- Hoses and ducts for leaks
- Air cleaner clogging
- Gasket
- Confirm that electrical or mechanical loads are not applied.
- Headlamp switch is OFF.
- Air conditioner switch is OFF.
- Rear window defogger switch is OFF.
- Steering wheel is in the straight-ahead position, etc.
- Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1, 000 RPM.
- Run engine at about 2, 000 RPM for about 2 minutes under no load.
- Make sure that no DTC is displayed with CONSULT or GST.
Is any DTC detected?
YES
GO TO STEP 2 .
NO
GO TO STEP 3 .
- REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
GO TO STEP 3 .
- CHECK TARGET IDLE SPEED
- Run engine at about 2, 000 RPM for about 2 minutes under no load.
- Rev engine (2, 000 to 3, 000 RPM) two or three times under no load, then run engine at idle speed for about 1 minute.
- Check idle speed.
For procedure, refer to INSPECTION .
For specification, refer to IDLE SPEED .
Is the inspection result normal?
YES
GO TO STEP 10 .
NO
GO TO STEP 4 .
- PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
- Stop engine.
- Perform WORK PROCEDURE .
GO TO STEP 5 .
- PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform WORK PROCEDURE .
GO TO STEP 6 .
- PERFORM IDLE AIR VOLUME LEARNING
Perform WORK PROCEDURE .
Is Idle Air Volume Learning carried out successfully?
YES
GO TO STEP 7 .
NO
Follow the instruction of Idle Air Volume Learning. Then GO TO STEP 4 .
- CHECK TARGET IDLE SPEED AGAIN
- Start engine and warm it up to normal operating temperature.
- Check idle speed.
For procedure, refer to INSPECTION .
For specification, refer to IDLE SPEED .
Is the inspection result normal?
YES
GO TO STEP 10 .
NO
GO TO STEP 8 .
- DETECT MALFUNCTIONING PART
Check the Following.
- Check camshaft position sensor (PHASE) and circuit. Refer to DTC LOGIC .
- Check crankshaft position sensor (POS) and circuit. Refer to DTC LOGIC .
Is the inspection result normal?
YES
GO TO STEP 9 .
NO
Repair or replace. Then GO TO STEP 4
- CHECK ECM FUNCTION
- Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but this is a rare case.)
- Perform initialization of NATS system and registration of all NATS ignition key IDs. Refer to WORK PROCEDURE .
GO TO STEP 4 .
- CHECK IGNITION TIMING
- Run engine at idle.
- Check ignition timing with a timing light.
For procedure, refer to INSPECTION
For specification, refer to IGNITION TIMING .
1 Timing indicator
Is the inspection result normal?
YES
INSPECTION END.
NO
GO TO STEP 11 .
- PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
- Stop engine.
- Perform WORK PROCEDURE .
GO TO STEP 12 .
- PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform WORK PROCEDURE .
GO TO STEP 13 .
- PERFORM IDLE AIR VOLUME LEARNING
Perform WORK PROCEDURE .
Is Idle Air Volume Learning carried out successfully?
YES
GO TO STEP 14 .
NO
Follow the instruction of Idle Air Volume Learning. Then GO TO STEP 4 .
- CHECK TARGET IDLE SPEED AGAIN
- Start engine and warm it up to normal operating temperature.
- Check idle speed.
For procedure, refer to INSPECTION .
For specification, refer to IDLE SPEED .
Is the inspection result normal?
YES
GO TO STEP 15 .
NO
GO TO STEP 17 .
- CHECK IGNITION TIMING AGAIN
- Run engine at idle.
- Check ignition timing with a timing light.
For procedure, refer to INSPECTION .
For specification, refer to IGNITION TIMING .
1 Timing indicator
Is the inspection result normal?
YES
INSPECTION END.
NO
GO TO STEP 16 .
- CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EXPLODED VIEW .
Is the inspection result normal?
YES
GO TO STEP 17 .
NO
Repair the timing chain installation. Then GO TO STEP 4 .
- DETECT MALFUNCTIONING PART
Check the following.
- Check camshaft position sensor (PHASE) and circuit. Refer to DTC LOGIC .
- Check crankshaft position sensor (POS) and circuit. Refer to DTC LOGIC .
Is the inspection result normal?
YES
GO TO STEP 18 .
NO
Repair or replace. Then GO TO STEP 4
- CHECK ECM FUNCTION
- Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but this is a rare case.)
- Perform initialization of NATS system and registration of all NATS ignition key IDs. Refer to WORK PROCEDURE .
GO TO STEP 4 .
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.