HVAC DTC Troubleshooting: 8
DTC indicator 8: A Short in the Recirculation Control Motor Circuit
NOTE: If other short circuit DTCs are indicated at the same time, there may be an open or short to body ground in the power (5 V) circuit.

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the OFF (LOCK) mode and then the ON mode.

?2.
Do the Self-Diagnostic Function with the HVAC control unit.

?3.
Check for DTCs.

Is DTC 8 indicated?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Intermittent failure. Check for loose wires or poor connections on the recirculation control motor circuit.?
2.
Determine possible failure area (SENSOR 5V/S5V line, others):

Determine possible failure area (SENSOR 5V/S5V line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
Recirculation control motor 7P connector

?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Recirculation control motor 7P connector: disconnected
Test point 1
Recirculation control motor 7P connector No. 3
Test point 2
Body ground


Is there about 5 V?

     
YES
     
     
     
The SENSOR 5V/S5V wire is OK. Go to step 3.
     
NO
     
     
     
Go to step 4.
3.
Determine possible failure area (recirculation control motor, others):

Determine possible failure area (recirculation control motor, others)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Recirculation control motor 7P connector: disconnected
Test point 1
Recirculation control motor 7P connector No. 2
Test point 2
Body ground


Is there about 5 V?

     
YES
     
     
     
     
NO
     
     
     
Go to step 6.
4.
Open wire check (SENSOR 5V/S5V line):

Open wire check (SENSOR 5V/S5V line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Recirculation control motor 7P connector: disconnected
Test point 1
HVAC control unit 32P connector No. 17
Test point 2
Body ground

Is there about 5 V?

     
YES
     
     
     
Repair an open in the wire between the HVAC control unit and the recirculation control motor.?
     
NO
     
     
     
Go to step 5.
5.
Shorted wire check (SENSOR 5V/S5V line):

Shorted wire check (SENSOR 5V/S5V line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
HVAC control unit 32P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
HVAC control unit 32P connector: disconnected
Recirculation control motor 7P connector: disconnected
Test point 1
HVAC control unit 32P connector No. 17
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire between the HVAC control unit and the recirculation control motor.?
     
NO
     
     
     
The SENSOR 5V/S5V wire is OK. Replace the HVAC control unit.?
6.
Shorted wire check (RFD-P/FRD-P line):

Shorted wire check (RFD-P/FRD-P line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
HVAC control unit 32P connector

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
HVAC control unit 32P connector: disconnected
Recirculation control motor 7P connector: disconnected
Test point 1
HVAC control unit 32P connector No. 21
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire between the HVAC control unit and the recirculation control motor.?
     
NO
     
     
     
The RFD-P/FRD-P wire is OK. Replace the HVAC control unit.?