Network & communication
Definition only
Lights the check engine lamp
U01B2: Lost Communication With Planetary Gear Set Control Module
Standardized SAE J2012 code · U01xx — Lost communication with modules
What does U01B2 mean?
ECU lost communication with planetary gear set control module (used in some hybrid powertrains for power split).
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- High Module unpowered
- Low Gateway module routing CAN messages incorrectly
- Low CAN terminating resistor (120 Ω) drifted out of spec
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of U01B2 on the same make and model first.
U01B2 in the community
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