ALL SWITCH/DIAL OPERATION DOES NOT RESPOND [FULL-AUTO AIR CONDITIONER]

id0703c1005400

DESCRIPTION
•  All switch/dial operation of climate control unit does not respond
•  Indicator light of climate control unit does not turn on
POSSIBLE CAUSE
•  Open circuit or short to ground in wiring harness between climate control unit terminal 1X and front body control module (FBCM) terminal 1C
•  Open circuit or short to power supply in wiring harness between climate control unit terminal 1G and body ground
•  Ground point floating, bad contact
•  Climate control unit malfunction


Diagnostic Procedure

•  When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Step

Inspection

Action
1*
INSPECT FRONT CLIMATE CONTROL UNIT IG2 SIGNAL
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the following terminals (wiring harness-side):
―  Climate control unit terminal 1X
•  Is the voltage B+?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and front body control module (FBCM) terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness.
Go to Step 3.
2*
INSPECT FRONT CLIMATE CONTROL UNIT GND SIGNAL
•  Measure the voltage at the following terminals (wiring harness-side):
―  Climate control unit terminal 1G
•  Is the voltage 0 V?
Yes
Replace the climate control unit, then go to the next step.
(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
No
Refer to the wiring diagram and verify if there is a common connector between the climate control unit terminal and ground point.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness.
Go to the next step.
3
VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR
•  Do the related parts operate according to the switch/dial operation of the climate control unit?
Yes
Troubleshooting completed.
Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.