U0100: Keine Kommunikation mit Motorsteuergerät (ECM/PCM)
Keine Kommunikation mit Motorsteuergerät (ECM/PCM): Other CAN-bus modules (TCM, ABS, Instrument Cluster) stopped receiving periodic CAN frames from the Engine Control Module.
| Trouble Code (DTC) | U0100 |
|---|---|
| Official SAE Definition | Keine Kommunikation mit Motorsteuergerät (ECM/PCM) |
| Vehicle Subsystem | network |
| Driving Severity | HIGH |
Observable Symptoms
- No-start / no-crank condition
- Multiple warning lights and cooling fan running at full speed
Most Probable Root Causes
- Blown ECM main power relay or fuse
- Corroded engine ground strap
- High-speed CAN-bus short or open termination resistor (should measure 60 Ω across CAN-H and CAN-L)
Step-by-Step Diagnostic Procedure
- Check ECM power supply fuses and main relay click with ignition on
- Measure resistance between OBD-II Pin 6 (CAN-H) and Pin 14 (CAN-L) with battery disconnected (target: ~60 Ω)