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
• Malfunction in center panel unit (Audio switch panel)
• Malfunction in refrigerant pressure switch
• Malfunction in PCM (A/C signal)
• Malfunction in PCM (IG1 signal)
• Malfunction in A/C compressor
• Malfunction in A/C relay
• Malfunction in evaporator temperature sensor

• 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 CENTER PANEL UNIT (AUDIO SWITCH PANEL) OR ELSEWHERE

• Does cool air blow out when terminal D of center panel unit (audio switch panel) connector (10-pin, A/C signal) is grounded?
Yes
Replace center panel unit (audio switch panel), 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 following terminal of PCM.
- Terminal AO (A/C signal)
• 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 CENTER PANEL UNIT (AUDIO SWITCH PANEL)) OR ELSEWHERE

• Test voltage at following terminal of center panel unit (audio switch panel).
- Terminal D (10-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 following terminal of PCM.
- Terminal AN (A/C relay control signal)
• 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.