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.
How To Proceed With Troubleshooting
HINT:
- Use these procedures to troubleshoot the window defogger system.
- *: Use the intelligent tester or Techstream.
- VEHICLE BROUGHT TO WORKSHOP
- INSPECT BATTERY VOLTAGE
Standard voltage: 11 to 14 V
If the voltage is below 11V, recharge or replace the battery before proceeding.
- INSPECT ELECTRIC POWER CONTROL SYSTEM*
- Using the intelligent tester or Techstream, check the electric power control system's load control history (see OPERATION CHECK ).
- INSPECT COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM*
- Use the intelligent tester or Techstream to check that the CAN communication system is functioning normally.
Result
RESULT CHARTResult Proceed to CAN DTC is not output A CAN DTC is output B
B: Go to CAN COMMUNICATION SYSTEM (see HOW TO PROCEED WITH TROUBLESHOOTING )
A: GO TO NEXT STEP
- Use the intelligent tester or Techstream to check that the CAN communication system is functioning normally.
- PROBLEM SYMPTOMS TABLE
- Refer to the PROBLEM SYMPTOMS TABLE
.
Result
RESULT CHARTResult Proceed to Fault is not listed in problem symptoms table A Fault is listed in problem symptoms table B
B: Go to step 7
A: GO TO NEXT STEP
- Refer to the PROBLEM SYMPTOMS TABLE
.
- OVERALL ANALYSIS AND TROUBLESHOOTING*
- Terminals of ECU (see TERMINALS OF ECU )
- DATA LIST / ACTIVE TEST (see DATA LIST / ACTIVE TEST )
- On-vehicle Inspection (see ON-VEHICLE INSPECTION )
- Inspection
- REPAIR OR REPLACE
- CONFIRMATION TEST
NEXT: END
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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.
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