A/C system does not come on (both fans and the A/C compressor do not work); heater is OK
Diagnostic procedure
  1. A/C signal circuit troubleshooting
  2. A/C pressure sensor troubleshooting: A/C pressure sensor circuit low voltage, L13Z1 engine, R18A2 engine, K20Z4 engine, A/C pressure sensor circuit high voltage, L13Z1 engine, R18A2 engine, K20Z4 engine
Also check for
  • HVAC DTCs
  • Powertrain DTCs
  • Cleanliness and tightness of all terminals