P2CD4
A/C Refrigerant Pressure Sensor A/B Correlation
The signals of A/C refrigerant pressure sensors A and B do not correlate within the calibrated tolerance. One sensor drifts or installation offset between the two channels.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- One sensor characteristic driftedCommon
- Harness incorrectly swapped between channelsPossible
Parts involved
- AC Refrigerant Pressure Sensor A
- AC Refrigerant Pressure Sensor B
- ECM
P2CD4 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.