Specifications

TROUBLESHOOTING
U75
U
End Of Si e
NO.8 NO COOL AIR
A6E858001038W10
• 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
8 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)
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 and 2.
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.7.
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 approximately 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 approximately 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 A 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 approximately 12 V?
Yes Go to Step 10.
No Repair wiring harness between refrigerant pressure switch
and climate control unit, then go to Step 17.