U0301high severityNetwork
Software Incompatibility with ECM/PCM
on 2002 Toyota Highlander 3.0L V6 · AWD
What this code means
The data protocol or software version from the ECM/PCM is incompatible with other vehicle modules.
Symptoms
- Check Engine Light
- Transmission shift issues
- Other modules reporting ECM data errors
- Systems not responding to ECM commands
Common causes
- ECM software version mismatch
- ECM reprogramming incomplete
- Wrong ECM software loaded
- ECM hardware revision mismatch
Diagnostic steps
- Check ECM software version
- Compare to required version
- Reprogram ECM with correct software
- Check for TSBs
- Verify ECM hardware part number matches software
Repair notes
Reprogram ECM/PCM with correct calibration. Verify correct part number and software version.
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Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus