Test D: The Air Conditioning (A/C) Is Always On

PINPOINT TEST D: THE AIR CONDITIONING (A/C) IS ALWAYS ON

CAUTION: It is important to install relays in their correct position in the battery junction box (BJB). Installing a relay incorrectly can cause wiring shorts or damage to modules. While carrying out diagnostics on BJB relays, have only one BJB relay removed at a time. Failure to follow these instructions may result in damage to the vehicle circuitry or to control modules.

NOTE: Before carrying out the following test, diagnose any PCM DTCs.

Normal Operation
Under normal operation, the function selector switch is supplied voltage through circuit CBP27 (GN/BN). When any mode requiring A/C is selected, the function selector switch sends voltage to the A/C high-pressure switch through circuit CH443 (GN/OG). Voltage is then supplied from the A/C high-pressure switch to the A/C cycling switch through circuit CH423 (YE). The voltage is then supplied from the A/C cycling switch to the PCM through circuit CH425 (GN/BU).

Voltage is supplied to the A/C clutch relay switch through circuit SBB25 (RD). When the relay is energized, voltage is sent to the A/C clutch through circuit CH401 (VT/WH). The A/C clutch is grounded through circuit GD121 (BK/YE).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- Function selector switch
- A/C control relay
- A/C clutch diode
- A/C clutch air gap

D1-D4:

D4-D6:

D6 Continued: