Mazda 6 2002, Workshop Manual

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TROUBLESHOOTING
U–71
U
Diagnostic procedure
POSSIBLE
CAUSE
•
Climate control unit (B+ signal) system malfunction (Steps 2, 4, 5)
•
Air intake actuator malfunction (Steps 3, 7)
•
Climate control unit (RECIRCULATE, FRESH signal) system malfunction (Steps 9—11)
•
Malfunction in blower unit air intake doors (Steps 12, 13)
STEP INSPECTION ACTION
1 COOL AIR BLOW OUT INSPECTION
•
When both A/C and fan switch in climate
control unit are on, does cool air blow out
from front vent?
Yes Go to next step.
No Go to Step 1 of troubleshooting index No.8.
2 INSPECT CLIMATE CONTROL UNIT POWER
SUPPLY FUSE FOR B+ SIGNAL
•
Is climate control unit power supply fuse for
B+ signal okay?
Yes Go to next step.
No Inspect for a short to ground on blown fuse circuit.
•
Repair or replace as necessary. Install appropriate
amperage fuse.
3 INSPECT AIR INTAKE ACTUATOR
•
Inspect air intake actuator.
— Is there grease on link?
— Is link securely and properly positioned?
— Is link free of obstructions?
•
Are above items okay?
Yes Go to next step.
No Apply grease or install link properly and securely, remove
obstruction, then go to Step 14.
*4 INSPECT WIRING HARNESS BETWEEN
FUSE BLOCK AND CLIMATE CONTROL UNIT
FOR CONTINUITY
•
Disconnect climate control unit connector
(12-pin).
•
Turn ignition switch to ON position.
•
Test voltage at climate control unit connector
terminal F (B+ signal).
•
Is voltage approximately 12 V ?
Yes Go to next step.
No Repair wiring harness between fuse block and climate
control unit, then go to Step 14.
*5 INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND GROUND
FOR VOLTAGE
•
Test voltage at climate control unit connector
terminal 2L (Ground).
•
Is voltage approximately 0V ?
Yes Go to next step.
No Repair wiring harness between climate control unit and
ground, then go to Step 14.
6 VERIFY WHETHER MALFUNCTION IS IN
BLOWER UNIT AIR INTAKE DOOR OR
ELSEWHERE
•
Turn ignition switch to LOCK position.
•
Connect climate control unit connector (12-
pin).
•
Remove air intake actuator.
•
Turn ignition switch to ON position.
•
Set fan switch to 4th position.
•
Does air intake mode (RECIRCULATE,
FRESH) change smoothly when air intake
link is operated by hand?
Yes Go to next step.
No Go to Step 12.
7 INSPECT AIR INTAKE ACTUATOR
•
Inspect air intake actuator.
(See
U–30 AIR INTAKE ACTUATOR
INSPECTION )
•
Is it okay?
Yes Go to next step.
No Replace air intake actuator, go to Step 14.
8 INSPECT AIR INTAKE SELECTOR SWITCH
AND DEFROSTER SWITCH IN CLIMATE
CONTROL UNIT
•
Test voltage at climate control unit connector
(12-pin) terminals 2K and 2I.
•
Is it okay?
Yes Go to next step.
No Replace climate control unit, then go to Step 14.