NO.11 NO COOL AIR

BME070301038213

11

No cool air

DESCRIPTION

• Magnetic clutch does not operate.

POSSIBLE CAUSE

• A/C compressor system malfunction
• Incorrect amount of refrigerant
• A/C switch indicator light malfunction
• PCM A/C cut-off control system
• PCM (IG1 signal) system malfunction
• Thermosensor, A/C switch malfunction
• PCM (A/C signal) system malfunction
• Refrigerant pressure switch malfunction
• PCM cooling fan control system
• A/C relay, magnetic clutch malfunction

• When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing 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

ACTION

1
INSPECT AIR BLOW OUT
• Does air blow out?
Yes
Go to next step.
No
Go to Step 1 of troubleshooting indexes No.1, 2, 6, and 7.
2
INSPECT A/C COMPRESOR OPERATION
• Start engine.
• Turn both A/C switch and front fan switch on.
• Does A/C compressor operate?
Yes
Go to Step 1 of troubleshooting index No.10.
No
Go to next step.
3
INSPECT REFRIGERANT AMOUNT
• Inspect refrigerant amount.
• Is it okay?
Yes
Go to next step.
No
Add or subtract refrigerant to specified level, then go to Step 28.
4
INSPECT A/C SWITCH INDICATOR LIGHT
• Does A/C switch indicator light illuminate?
Yes
Go to Step 8.
No
Go to next step.
*5
INSPECT WIRING HARNESS BETWEEN FUSE BLOCK AND FRONT CLIMATE CONTROL UNIT FOR CONTINUITY
• Turn ignition switch to ON position.
• Turn both A/C switch and front fan switches on.
• Remove airflow mode wire, and air mix wire and pull out front climate control unit.
• Test voltage at front climate control unit terminal B (IG2 signal).
• Is voltage approximately B+?
Yes
Go to next step.
No
Repair wiring harness between fuse block and front climate control unit, then go to Step 28.
*6
INSPECT WIRING HARNESS BETWEEN FRONT CLIMATE CONTROL UNIT AND RESISTOR FOR CONTINUITY
• Turn ignition switch to ON position.
• Turn front fan switch off.
• Test voltage at front climate control unit connector terminal F (blower fan signal).
• Is voltage approximately B+?
Yes
Go to next step.
No
Inspect wiring harness between front climate control unit and resistor, then go to Step 28.
*7
VERIFY WHETHER MALFUNCTION IS IN WIRING HARNESS (BETWEEN FRONT CLIMATE CONTROL UNIT AND GROUND FOR CONTINUITY) OR FRONT CLIMATE CONTROL UNIT
• Turn ignition switch to LOCK position.
• Is there continuity between front climate control unit connector terminal D (GND signal) and ground?
Yes
Replace front climate control unit, then go to Step 28.
No
Repair wiring harness between front climate control unit and ground, then go to Step 28.
8
CHECK FOR DTCS IN PCM
• Check the DTC for the ON-BOARD DIAGNOSTIC (ENGINE CONTROL).
• Are any DTCs displayed?
Yes
Go to appropriate inspection procedure. (The PCM's A/C cut off control input signal may be the cause of the trouble.)
No
Go to next step.
*9
VERIFY WHETHER MALFUNCTION IS IN MAGNETIC CLUTCH SYSTEM OR ELSEWHERE
• Remove A/C relay.
• Turn ignition switch to ON position.
• When A/C relay connector terminal C and D (on wiring harness side) are shorted, does magnetic clutch operate?
Yes
Go to next step.
No
Go to Step 24.
*10
VERIFY WHETHER MALFUNCTION IS IN THERMOSENSOR SYSTEM OR ELSEWHERE
• Turn ignition switch to LOCK position.
• Disconnect refrigerant pressure switch connector.
• Turn ignition switch to ON position.
• Set front fan switch at first speed.
• Test voltage at the following refrigerant pressure switch connector terminals (A/C signal) on wiring harness side.
- Terminal C
• Is voltage approximately B+ when A/C switch is off and 0 V when it is on?
Yes
Go to Step 16.
No
Reconnect refrigerant pressure switch connector, then go to next step.
*11
VERIFY WHETHER MALFUNCTION IS IN THERMOSENSOR AND WIRING HARNESS (BETWEEN FUSE BLOCK AND THERMOSENSOR FOR CONTINUITY) OR ELSEWHERE
• Disconnect thermosensor connector.
• Start engine.
• Turn both A/C switch and front fan switches on.
• When thermosensor connector terminals B and C (on wiring harness side) are shorted, does cool air blow out?
Yes
Undo short, then go to next step.
No
Undo short, then go to Step 13.
*12
VERIFY WHETHER MALFUNCTION IS IN THERMOSENSOR OR WIRING HARNESS (BETWEEN FUSE BLOCK AND THERMOSENSOR FOR CONTINUITY)
• Turn ignition switch to ON position.
• Test voltage at thermosensor connector terminal A (IG2 signal) on wiring harness side.
• Is voltage approximately B+?
Yes
Inspect thermosensor, then go to Step 28.
No
Repair wiring harness between fuse block and thermosensor, then go to Step 28.
*13
INSPECT WIRING HARNESS BETWEEN THERMOSENSOR AND REFRIGERANT PRESSURE SWITCH FOR SHORT TO B+
• Turn ignition switch to ON position.
• Test voltage at thermosensor connector terminal C (A/C signal) on wiring harness side.
• Is voltage approximately B+?
Yes
Repair wiring harness between thermosensor and refrigerant pressure switch, then go to Step 28.
No
Go to next step.
*14
INSPECT WIRING HARNESS BETWEEN THERMOSENSOR AND REFRIGERANT PRESSURE SWITCH FOR CONTINUITY
• Turn ignition switch to LOCK position.
• Inspect for continuity between the following thermosensor connector terminals (A/C signal) and refrigerant pressure switch connector terminals.
- Terminal C-Terminal C
• Is there continuity?
Yes
Go to next step.
No
Repair wiring harness between refrigerant pressure switch and thermosensor, then go to Step 28.
*15
INSPECT WIRING HARNESS BETWEEN FRONT CLIMATE CONTROL UNIT AND THERMOSENSOR FOR CONTINUITY
• Is there continuity between front climate control unit connector terminal I and thermosensor connector terminal B.
Yes
Replace front climate control unit.
No
Repair wiring harness between front climate control unit and thermosensor.
*16
VERIFY WHETHER MALFUNCTION IS IN PCM AND WIRING HARNESS (BETWEEN PCM AND REFRIGERANT PRESSURE SWITCH FOR CONTINUITY) OR ELSEWHERE
• Turn ignition switch to ON position.
• Test voltage at the following refrigerant pressure switch connector (on wiring harness side) terminal (A/C signal).
- Terminal A
• Is voltage approximately B+?
Yes
Go to Step 18.
No
Go to next step.
*17
VERIFY WHETHER MALFUNCTION IS IN PCM OR WIRING HARNESS (BETWEEN PCM AND REFRIGERANT PRESSURE SWITCH FOR CONTINUITY)
• Test voltage at the following PCM connector terminal (A/C signal).
- (For AJ) Terminal 5
- (For L3) Terminal AC
- (For RF) Terminal 84
• Is voltage approximately B+?
Yes
Repair wiring harness between PCM and refrigerant pressure switches, then go to Step 28.
No
Inspect PCM, then go to Step 28.
*18
VERIFY WHETHER MALFUNCTION IS IN REFRIGERANT PRESSURE SWITCH OR ELSEWHERE
• When the following refrigerant pressure switch connector terminals (on wiring harness side) are shorted, does cool air blow out?
- Terminal A-Terminal C
Yes
Inspect refrigerant pressure switch, then go to Step 28.
No
Undo short, reconnect refrigerant pressure switch connector, then go to next step.
*19
VERIFY WHETHER MALFUNCTION IS IN A/C RELAY SYSTEM (COIL-SIDE) OR ELSEWHERE
• Turn ignition switch to ON position.
• Turn A/C switch off.
• Test voltage at the following PCM connector terminals (IG1 signal).
- (For AJ) Terminal 47
- (For L3) Terminal 4O
- (For RF) Terminal 73
• Is voltage approximately B+?
Yes
Go to Step 23.
No
Go to next step.
*20
INSPECT A/C RELAY (COIL-SIDE) POWER SUPPLY FUSE
• Is A/C relay power supply fuse okay?
Yes
Go to next step.
No
Inspect blown fuse's circuit for short to ground.
Repair or replace as necessary.
Install appropriate amperage fuse.
*21
INSPECT WIRING HARNESS BETWEEN FUSE BLOCK AND A/C RELAY (COIL-SIDE) FOR CONTINUITY
• Turn ignition switch to ON position.
• Test voltage at A/C relay connector terminal A (IG2 signal).
• Is voltage approximately B+?
Yes
Go to next step.
No
Repair wiring harness between fuse block and A/C relay, then go to Step 28.
*22
INSPECT A/C RELAY (COIL-SIDE)
• Inspect A/C relay.
• Is it okay?
Yes
Repair wiring harness between A/C relay and PCM (terminal 69), then go to Step 28.
No
Replace A/C relay, then go to Step 28.
*23
INSPECT COOLANT SYSTEM OPERATION
• Inspect cooling system operation.
Yes
Go to next step.
No
Go to appropriate inspection procedure.
24
INSPECT A/C RELAY (SWITCH-SIDE) POWER SUPPLY FUSE
• Is A/C relay power supply fuse okay?
Yes
Go to next step.
No
Inspect blown fuse's circuit for short to ground. Repair or replace as necessary.
Install appropriate amperage fuse.
*25
INSPECT WIRING HARNESS BETWEEN FUSE BLOCK AND A/C RELAY (SWITCH-SIDE) FOR CONTINUITY
• Turn ignition switch to ON position.
• Test voltage at A/C relay connector terminal D (A/C control signal)
• Is voltage approximately B+?
Yes
Go to next step.
No
Repair wiring harness between fuse block and A/C relay, then go to Step 28.
*26
INSPECT A/C RELAY (SWITCH-SIDE)
• Inspect A/C relay.
• Is it okay?
Yes
Install A/C relay, go to next step.
No
Replace A/C relay, then go to Step 28.
*27
VERIFY WHETHER MALFUNCTION IS IN MAGNETIC CLUTCH OR WIRING HARNESS (BETWEEN A/C RELAY AND MAGNETIC CLUTCH FOR CONTINUITY)
• Test voltage at magnetic clutch connector terminal A (A/C control signal).
• Is voltage approximately B+?
Yes
Inspect magnetic clutch, then go to next step.
No
Repair wiring harness between A/C relay and magnetic clutch, then go to next step.
28
VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR
• Does cool air blow out? (Is refrigerant system performance test result correct?)
Yes
Troubleshooting completed. Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.