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NO.5 NO COOL AIR

id070300802600

5 | No cool air
DESCRIPTION | • Magnetic clutch does not operate.
POSSIBLE CAUSE | • Malfunction in PCM A/C cut control system (Step 3) • Malfunction in climate control unit (Step 4) • Malfunction in refrigerant pressure switch (Steps 5, 7-9) • Malfunction in PCM (A/C signal) (Step 6) • Malfunction in PCM (IG1 signal) (Steps 10, 11) • Malfunction in A/C compressor (Step 12) • Malfunction in A/C relay (Steps 13-15) • Malfunction in evaporator temperature sensor (Step 16)

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Diagnostic procedure

Step | Inspection | Inspection item (s)
--- | --- | ---
1 | INSPECT AIR BLOW OUT • Does air blow out? | Yes | Go to next step.
No | Go to Step 1 of troubleshooting index No.1.
2 | INSPECT A/C COMPRESSOR OPERATION • Start engine. • Turn A/C switch and fan switch on. • Does A/C compressor operate? | Yes | Go to Step 1 of troubleshooting index No.4.
No | Go to next step.
3 | INSPECT FOR DTC IN PCM • Inspect for DTCs related to the PCM on-board diagnostic system. • Are any DTCs displayed? | Yes | Go to appropriate inspection procedure.
No | Go to next step.
4 | INSPECT TO SEE WHETHER MALFUNCTION IS IN CLIMATE CONTROL UNIT OR ELSEWHERE • Does cool air blow out when terminal 1P of climate control unit connector (24-pin, A/C signal) is grounded? | Yes | Replace climate control unit, then go to Step 17.
No | Release short, then go to next step.
5* | INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C SIGNAL CIRCUIT (BETWEEN REFRIGERANT PRESSURE SWITCH AND PCM) OR ELSEWHERE • Test voltage at following terminal of refrigerant pressure switch. - Terminal B (A/C signal) • Is voltage approx. 12 V? | Yes | Go to Step 7.
No | Go to next step.
6* | INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN WIRING HARNESS (BETWEEN REFRIGERANT PRESSURE SWITCH AND PCM) OR PCM • Test voltage at A/C signal terminal of PCM. • Is voltage approx. 12 V? | Yes | Repair wiring harness between PCM and refrigerant pressure switch, then go to Step 17.
No | Inspect PCM, then go to Step 17.
7 | INSPECT TO SEE WHETHER MALFUNCTION IS IN REFRIGERANT PRESSURE SWITCH, REFRIGERANT AMOUNT, OR ELSEWHERE • Does cool air blow out when terminals C and B of refrigerant pressure switch connector are shorted? | Yes | Go to Step 9.
No | Go to next step.
8* | INSPECT TO SEE WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN REFRIGERANT PRESSURE SWITCH AND CLIMATE CONTROL UNIT) OR ELSEWHERE • Test voltage at following terminal of climate control unit. - Terminal 1P (24-pin, A/C signal) • Is voltage approx. 12 V? | Yes | Go to Step 10.
No | Repair wiring harness between refrigerant pressure switch and climate control unit, then go to Step 17.
9 | INSPECT TO SEE WHETHER MALFUNCTION IS IN REFRIGERANT PRESSURE SWITCH OR REFRIGERANT AMOUNT • Inspect refrigerant pressure switch. • Is it normal? | Yes | If refrigerant amount is empty, replace condenser, vacuum refrigerant line 30 min or more by vacuum pump, and add refrigerant to specified level, then go to Step 17.
No | Replace refrigerant pressure switch, then go to Step 17.
10 | INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN A/C CONTROL SIGNAL CIRCUIT (BETWEEN A/C RELAY AND PCM) OR ELSEWHERE • Does cool air blow out when terminal E of A/C relay connector (A/C control signal) is grounded? | Yes | Release short, then go to next step.
No | Go to Step 12.
11* | INSPECT TO SEE WHETHER MALFUNCTION (LACK OF CONTINUITY) IS IN PCM OR WIRING HARNESS (BETWEEN A/C RELAY AND PCM) • Test voltage at the A/C relay control signal terminal of PCM. • Is voltage approx. 12 V? | Yes | Inspect PCM, then go to Step 17.
No | Repair wiring harness between A/C relay and PCM, then go to Step 17.
12* | INSPECT TO SEE WHETHER MALFUNCTION IS IN MAGNETIC CLUTCH OR ELSEWHERE • Test voltage at the following terminal of magnetic clutch. - Terminal A (magnetic clutch operation signal) • Is voltage approx. 12 V? | Yes | Inspect magnetic clutch, then go to Step 17.
No | Go to next step.
13 | INSPECT FUSE • Are A/C relay power supply fuses normal? | Yes | Go to next step.
No | Replace fuse, then go to Step 17. If fuse burns out immediately, go to next step.
14 | INSPECT WIRING HARNESS BETWEEN FUSE BLOCK AND A/C RELAY FOR LACK OF CONTINUITY • Test voltages at following terminals of A/C relay. - Terminal A (A/C relay control signal) - Terminal C (A/C control signal) • Are voltages approx. 12 V? | Yes | Go to next step.
No | Repair wiring harness between fuse block and A/C relay, then go to Step 17.
15 | INSPECT TO SEE WHETHER MALFUNCTION IS IN A/C RELAY OR WIRING HARNESS (BETWEEN A/C RELAY AND MAGNETIC CLUTCH) AND EVAPORATOR TEMPERATURE SENSOR • Test voltage at the following terminal of A/C relay. - Terminal D (magnetic clutch operation signal) • Is voltage approx. 12 V? | Yes | Inspect wiring harness between A/C relay and magnetic clutch. • If above wiring harness is normal, go to next step. • If above wiring harness malfunctions, repair wiring harness, then go to Step 17.
No | Replace A/C relay, then go to Step 17.
16 | INSPECT EVAPORATOR TEMPERATURE SENSOR • Inspect evaporator temperature sensor. • Is it normal? | Yes | Go to next step.
No | Replace evaporator temperature sensor, then go to next step.
17 | CONFIRM THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR • Does cool air blow out? (Are the results of refrigerant system performance test normal?) | Yes | Troubleshooting completed. Explain repairs to customer.
No | Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.