What does fault code U0100 mean?
Diagnostic trouble code U0100 is defined as Lost Communication With ECM/PCM "A". This standard OBD2 code is triggered when your car's powertrain or module sensor voltage deviates from calibrated safety tolerances.
Severity & Can I Drive With Code U0100?
Severity Rating: 5/5 (High Severity)
⚠️ Drivability Warning: Prolonged driving with this code is not recommended. Prompt repair is suggested to prevent secondary component damage.
Common Symptoms of U0100
- Car won't crank
- All dash warning lights on (ABS, Airbag, Check Engine)
Common Causes Ranked by Likelihood
- Blown ECM main power fuse
- Corroded CAN bus wire
- Dead 12V battery
DIY Repair & Troubleshooting Steps
- Check ECM main power fuses & relays
- Test battery voltage
Professional Shop Repair & Estimated Cost Range
- Trace CAN high/low bus wiring
- Replace ECM
Estimated Repair Cost Range: $100 - $1,500
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