Mazda CX-7 2007 Workshop Manual page 1113

DTC B1251, B1253
DTC B1251,
Passenger compartment temperature sensor system
B1253
• Passenger compartment temperature sensor malfunction
POSSIBLE
• Open or short circuit in wiring harness between climate control unit and passenger compartment
CAUSE
temperature sensor
Diagnostic Procedure
STEP
• Inspect the passenger compartment temperature
1
sensor. (See 07-40-23 PASSENGER
COMPARTMENT TEMPERATURE SENSOR
INSPECTION.)
• Is it normal?
• Disconnect the climate control unit connector and
2
the passenger compartment temperature sensor
connector.
• Is there an open circuit in the wiring harness
between the following terminals of the climate
control unit and the passenger compartment
temperature sensor?
— H— B
— C— A
• Is there a short circuit to ground in the wiring
3
harness between climate control unit terminal H
and passenger compartment temperature sensor
terminal B?
• Turn the ignition switch to the ON position.
4
• Inspect the voltage at the following climate control
unit terminal (wiring harness-side).
— Terminal H (passenger compartment
temperature sensor input signal)
• Is the voltage normal? (Approx. 5 V)
CLIMATE CONTROL UNIT CONNECTOR
Q O
W U S
X V T R P
End Of Sie
ON-BOARD DIAGNOSTIC
INSPECTION
M K I G C A
E
L H D
N J F B
Yes Go to the next step.
No Replace the passenger compartment temperature
sensor. (See 07-40-23 PASSENGER COMPARTMENT
TEMPERATURE SENSOR REMOVAL/
INSTALLATION.)
Yes Repair the wiring harness.
No Go to the next step.
Yes Repair the wiring harness.
No Connect the climate control unit connector, then go to
the next step.
Yes The system is normal at present. (Clear the malfunction
from the memory.)
No Inspect the connection of the climate control unit
connector. (See 07-40-13 CLIMATE CONTROL UNIT
INSPECTION [FULL-AUTO AIR CONDITIONER].)
PASSENGER COMPARTMENT TEMPERATURE
SENSOR CONNECTOR
B
id070200800300
ACTION
A
07-02–3
07-02