Test Km: A/C Relay Circuit: Testing

NOTE: For A/C relay fault, start testing at step 1). For all other concerns, start testing at step 10).

1) Check PWR Circuit To A/C Relay
Turn ignition off. Remove A/C relay from left side engine compartment relay block. See Figure. Turn ignition on. Using DVOM, measure voltage between chassis ground and PWR circuit at A/C relay cavity No. 2. See Figure. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open in PWR circuit. See WIRING DIAGRAMS in AUTOMATIC A/C-HEATER SYSTEMS - VILLAGER or MANUAL A/C-HEATER SYSTEMS - VILLAGER article.

2) Perform A/C Relay Click Test

Turn ignition off. Install A/C relay. Disconnect PCM harness connector. Inspect connector for damaged pins and repair if necessary. Turn ignition on. Connect a jumper wire between chassis ground and A/C SIG circuit at PCM harness connector terminal No. 12. See Figure. If A/C relay does not click, go to next step. If A/C relay clicks when A/C SIG circuit is grounded, replace PCM.

3) Check ACR Circuit For Open

Turn ignition off. Remove A/C relay. Using DVOM, measure resistance of A/C SIG circuit (Light Green wire) between A/C relay cavity No. 1 and PCM harness connector terminal No. 12. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in A/C SIG circuit. See WIRING DIAGRAMS in AUTOMATIC A/C-HEATER SYSTEMS - VILLAGER or MANUAL A/C-HEATER SYSTEMS - VILLAGER article.

4) Check A/C SIG Circuit To PCM For Short To Ground

Using DVOM, measure resistance between chassis ground and A/C SIG circuit at PCM harness connector terminal No. 12. See Figure. If resistance is more than 10 k/ohms, replace A/C relay. If resistance is 10 k/ohms or less, repair short to ground in A/C SIG circuit.
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 10). No test procedures have been omitted.

10) Check Ground Circuit To A/C High Pressure Switch

Turn ignition off. Disconnect A/C high pressure switch. Using DVOM, measure resistance between chassis ground and GND circuit at high pressure switch harness connector terminal No. 2 (Black wire). See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in ground circuit. See WIRING DIAGRAMS in AUTOMATIC A/C-HEATER SYSTEMS - VILLAGER or MANUAL A/C-HEATER SYSTEMS - VILLAGER article.

11) Check PCM REF Circuit To PCM For Open

Using DVOM, measure resistance of PCM REF circuit (Blue/Black wire) between PCM harness connector terminal No. 9 and A/C high pressure switch harness connector terminal No. 4. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in PCM REF circuit.

12) Check PCM REF Circuit To PCM For Short To Ground

Using DVOM, measure resistance between chassis ground and PCM REF circuit at PCM harness connector terminal No. 9 (Blue/Black wire). See Figure. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in PCM REF circuit. See WIRING DIAGRAMS in AUTOMATIC A/C-HEATER SYSTEMS - VILLAGER or MANUAL A/C-HEATER SYSTEMS - VILLAGER article.

13) Check A/C High Pressure Switch

Perform high pressure switch testing procedures in A/C DOES NOT OPERATE/DOES NOT OPERATE CORRECTLY and A/C ALWAYS ON symptom tests in MANUAL or AUTOMATIC A/C-HEATER SYSTEMS - VILLAGER article in AIR CONDITIONING & HEATING. Replace high pressure switch as necessary. If high pressure switch is okay and no problem is found with circuit, replace PCM.