Mazda 2002 6 Workshop Manual page 1222

• Climate control unit (B+ signal) system malfunction (Steps 2, 4, 5)
• Air intake actuator malfunction (Steps 3, 7)
POSSIBLE
• Climate control unit (RECIRCULATE, FRESH signal) system malfunction (Steps 9—11)
CAUSE
• Malfunction in blower unit air intake doors (Steps 12, 13)
Diagnostic procedure
STEP
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?
2 INSPECT CLIMATE CONTROL UNIT POWER
SUPPLY FUSE FOR B+ SIGNAL
• Is climate control unit power supply fuse for
B+ signal okay?
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?
*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?
*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?
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?
7 INSPECT AIR INTAKE ACTUATOR
• Inspect air intake actuator.
(See U–30 AIR INTAKE ACTUATOR
INSPECTION)
• Is it okay?
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?
TROUBLESHOOTING
INSPECTION
Yes Go to next step.
No Go to Step 1 of troubleshooting index No.8.
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.
Yes Go to next step.
No Apply grease or install link properly and securely, remove
obstruction, then go to Step 14.
Yes Go to next step.
No Repair wiring harness between fuse block and climate
control unit, then go to Step 14.
Yes Go to next step.
No Repair wiring harness between climate control unit and
ground, then go to Step 14.
Yes Go to next step.
No Go to Step 12.
Yes Go to next step.
No Replace air intake actuator, go to Step 14.
Yes Go to next step.
No Replace climate control unit, then go to Step 14.
ACTION
U–71
U