Mazda CX-7 2007 Workshop Manual page 1378

DTC B2175[BCM]
DTC B2175 A/C request switch circuit short to ground
DETECTION Short to GND in wiring harness between BCM and climate control unit (A/C ON request)
CONDITION
• Short to GND in wiring harness between BCM terminal 3V and climate control unit terminal J
POSSIBLE
• Climate control unit malfunction
CAUSE
• BCM malfunction
CLIMATE CONTROL UNIT
CLIMATE CONTROL UNIT WIRING
HARNESS-SIDE CONNECTOR
W U S Q
X V T R
Diagnostic procedure
STEP
1 INSPECT CLIMATE CONTROL UNIT
CONNECTOR
• Disconnect the climate control unit
connector.
• Inspect the climate control unit connector
terminals for poor connection (such as
damaged/pulled-out pins, and corrosion).
• Is there any malfunction?
2 INSPECT BCM CONNECTOR
• Disconnect the BCM connector.
• Inspect the BCM connector terminals for
poor connection (such as damaged/pulled-
out pins, and corrosion).
• Is there any malfunction?
3 INSPECT CLIMATE CONTROL UNIT SIGNAL
CIRCUIT FOR SHORT TO GND
• Inspect for continuity between BCM terminal
3V (wiring harness-side) and body GND.
• Is there continuity?
4 INSPECT CLIMATE CONTROL UNIT
• Inspect the climate control unit.
(See 07-40-16 CLIMATE CONTROL UNIT
INSPECTION [MANUAL AIR
CONDITIONER].)
• Is there any malfunction?
5 VERIFY TROUBLESHOOTING COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC from the BCM memory using
the M-MDS.
• Perform the self-test.
(See 09-02F-26 BCM SELF-TEST[BCM].)
• Is the same DTC present?
End Of Sie
09-02F–16
ON-BOARD DIAGNOSTIC [BCM]
J
O M K I G E C A
P N L J H F D B
INSPECTION
BCM
3V
BCM WIRING HARNESS-SIDE
CONNECTOR
3W 3U 3S 3Q 3O 3M 3K
3X 3V 3T 3R 3P 3N 3L
Yes Repair or replace the terminal, then go to Step 5.
No Go to the next step.
Yes Repair or replace the terminal, then go to Step 5.
No Go to the next step.
Yes Repair or replace the wiring harness for a possible short to
GND, then go to Step 5.
No Go to the next step.
Yes Replace the climate control unit, then go to the next step.
(See 07-40-25 CLIMATE CONTROL UNIT REMOVAL
[MANUAL AIR CONDITIONER], 07-40-26 CLIMATE
CONTROL UNIT INSTALLATION [MANUAL AIR
CONDITIONER].)
No Go to the next step.
Yes Replace the BCM.
(See 09-40-1 BODY CONTROL MODULE (BCM)
REMOVAL/INSTALLATION.)
No DTC troubleshooting completed.
id0902f5832400
3I 3G 3E 3C 3A
3J 3H 3F 3D 3B
ACTION