Mazda CX-9 Grand Touring 2009 Manual page 1761

INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (OPEN CIRCIT
BETWEEN REAR BLOWER RELAY AND
GROUND) OR ELSEWHERE
5*
Measure the voltage at the following rear blower
relay terminal.
Terminal E (GND signal)
Is the voltage approx. 0 V?
INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (OPEN OR SHORT
CIRCUIT BETWEEN REAR BLOWER RELAY
AND REAR BLOWER MOTOR) OR
ELSEWHERE
6*
Measure the voltage at the following rear blower
relay terminal.
Terminal B (blower motor operation signal)
Is the voltage approx. 12 V?
INSPECT TO SEE WHETHER MALFUNCTION
IS IN REAR BLOWER MOTOR OR ELSEWHERE
Measure the voltage at the following rear blower
7*
motor terminal.
Terminal A (blower motor operation signal)
Is the voltage approx. 12 V?
INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (OPEN OR SHORT
CIRCUIT BETWEEN REAR BLOWER MOTOR
AND REAR POWER MOS FET) OR ELSEWHERE
8*
Measure the voltage at the following rear power
MOS FET terminal.
Terminal B (blower motor operation signal)
Is the voltage approx. 12 V?
INSPECT TO SEE WHETHER MALFUNCTION
IS IN WIRING HARNESS (OPEN CIRCUIT
BETWEEN REAR POWER MOS FET AND
GROUND) OR ELSEWHERE
9*
Is there continuity at the following terminals?
Terminal (wiring harness-side connector)
A-GND
INSPECT REAR A/C UNIT
2008 Mazda CX-9 Grand Touring
2008 HVAC Symptom Troubleshooting (HVAC) - Mazda CX-9
Yes Go to the next step.
Repair or replace for open circuit
No between rear blower relay and GND,
then go to Step 13.
Repair or replace for open or short
circuit between rear blower relay and
Yes
rear blower motor, then go to Step
13.
Replace the rear blower relay, then
No
go to Step 13.
Yes Go to the next step.
Replace the rear blower motor, then
No
go to Step 13.
Yes Go to the next step.
Repair or replace for open or short
circuit between rear blower motor
No
and rear power MOS FET, then go to
Step 13.
Yes Go to the next step.
Repair or replace for open circuit
No between rear power MOS FET and
GND, then go to Step 13.