Conditions for Running the DTC
WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
P156A
- Vehicle ON
- None of these DTCs are set: P0532, P0533, or U016B
- The compressor has been OFF for more than 20 s.
- The ECM monitors the A/C high side pressure every 100 ms when the above conditions are met.
P156B
- Vehicle ON
- None of these DTCs are set: P0532, P0533, or U016B
- The compressor has been ON for more than 10 s.
- The ECM monitors the A/C high side pressure every 100 ms when the above conditions are met.
P156A
- P156A is a type B DTC
- The ECM detects the A/C high side pressure is too high based on the current operating conditions.
P156B
- P156B is a type B DTC
- The ECM detects the A/C high side pressure is too low based on the current operating conditions.