P1530

Code P1503, A/C Head Pressure Switch Circuit:

A/C Head Pressure Switch Circuit:

*** This information has been updated according to Technical Service Bulletin #416507, dated April 1994.

CIRCUIT DESCRIPTION
The A/C head pressure switch opens at 200-220 psi (1379-1516 kPa). When the head pressure switch interrupts the ground at PCM CKT 380, the left fan should run at high speed.

DTC P1530 WILL SET WHEN:
^ The CKT 380 is grounded during the first 6 seconds of engine run time.
^ Engine coolant temperature is less than 31°C (88°F).
^ Ambient air temperature is less than 28°C (82°F).
^ RPM is less than 1800.
^ No DTC P0101, P0112, P0113, P0117, or PO118 is set.
^ All the above conditions must be met at the same time.

ACTION TAKEN (PCM will default to):
If current DTC P1530 is set, the left side cooling fan will run at high speed anytime A/C is requested. DTC P1530 does not illuminate the MIL (Service Engine Soon).

DIAGNOSTIC AIDS
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation.

Check for:
^ Poor connection or damaged harness Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection, and damaged harness.