P0D7B is the second phase U current code of the electric A/C compressor. In GM's first-generation Volt (2011–2015) and the 2016 Cadillac ELR it sets when the phase U current sensor reads −68 A or less although the motor is stopped and no speed is requested, counted as 30 failures in 60 samples at 50 ms; Type B, MIL after two trips, with a 12 V reset required before a pass. A real current of that size at standstill is impossible, so the fault lies in the sensor or its evaluation on the inverter board, which normally means replacing the compressor. The A/C stays off while the code is active. GM's positive-direction code for the same phase is P0D7A; phases V and W use P0D7D and P0D7F.
Low severity. Can I keep driving?Yes, you can keep driving. The air conditioning may not work.
Symptoms
- Check engine light after two trips
- Air conditioning stays off
Most likely causes
- Phase U current sensor reading negative at standstill
- Fault in the inverter's current evaluation
What to check, in order
Start with the simplest. You can tick off each step.
What each character of P0D7B means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- D: Subsystem depends on the code range
- 7B: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0D7B?
Yes, you can keep driving. The air conditioning may not work.
What causes code P0D7B?
The most common causes are: phase U current sensor reading negative at standstill; fault in the inverter's current evaluation.
Related codes
- P0D7AA/C Compressor Motor Phase U Current Low
- P0D7DA/C Compressor Motor Phase V Current High
- P0D7FA/C Compressor Motor Phase W Current High
- P0D6FA/C Compressor Motor Current High
Sources
- gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
- gsi.ext.gm.com: 14OBDG01 Hybrid Diagnostics
- gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.