DTC Troubleshooting: B1237 (44)

DTC B1237 or DTC indicator 44: A Short in the Passenger's Air Mix 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.

DTC Description	DTC
B1237 A short in the passenger's air mix control motor circuit

Problem verification:

Problem verification

?1.	Clear the DTC with the HDS.

?2.	Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.

?3.	Do the Self-Diagnostic Function with the HDS or the climate control unit.

?4.

Check for DTCs.

DTC Description	DTC
B1237 A short in the passenger's air mix control motor circuit

Is DTC B1237 or 44 indicated?


	YES

Go to step 2.


	NO

Intermittent failure. Check for loose wires or poor connections on the passenger's air mix control motor circuit.?

Open wire check (S 5V/S5V line):

Open wire check (S 5V/S5V line)

?1.	Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.

Disconnect the following connectors.

Climate control unit 32P connector

Passenger's air mix control motor 7P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	Climate control unit 32P connector: disconnected
	Passenger's air mix control motor 7P connector: disconnected
Test circuit	S 5V/S5V
Test point 1	Climate control unit 32P connector No. 24 (BLK)
Test point 2	Passenger's air mix control motor 7P connector No. 1 (BLK)

Is there continuity?


	YES

The S 5V/S5V wire is not open. Go to step 3.


	NO

Repair an open in the wire between the climate control unit and the passenger's air mix control motor.?

Shorted wire check (AMD-P AS/AMD-P-AS line to SENSOR COM/SENS-COM line):

Shorted wire check (AMD-P AS/AMD-P-AS line to SENSOR COM/SENS-COM line)

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	Climate control unit 32P connector: disconnected
	Passenger's air mix control motor 7P connector: disconnected
Test circuit	AMD-P AS, SENSOR COM
Test point 1	Climate control unit 32P connector No. 11 (PUR)
Test point 2	Climate control unit 32P connector No. 22 (BLU)

Is there continuity?


	YES

Repair a short in the wires between the climate control unit and the passenger's air mix control motor.?


	NO

The AMD-P AS/AMD-P-AS wire to SENSOR COM/SENS-COM wire are not shorted. Go to step 4.

Shorted wire check (AMD-P AS/AMD-P-AS line):

Shorted wire check (AMD-P AS/AMD-P-AS line)

?1.

Check for continuity between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	Climate control unit 32P connector: disconnected
	Passenger's air mix control motor 7P connector: disconnected
Test circuit	AMD-P AS
Test point 1	Climate control unit 32P connector No. 11 (PUR)
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to body ground in the wire between the climate control unit and the passenger's air mix control motor.?


	NO

The AMD-P AS/AMD-P-AS wire is OK. Go to step 5.

Passenger's air mix control motor internal resistance check (S5V and SENS-COM):

Passenger's air mix control motor internal resistance check (S5V and SENS-COM)

?1.

Measure the resistance between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
	Climate control unit 32P connector: disconnected
	Passenger's air mix control motor 7P connector: disconnected
Test circuit	S5V, SENS-COM
Test point 1	Passenger's air mix control motor No. 1
Test point 2	Passenger's air mix control motor No. 3

Is the resistance 6 k?

1.8 k??


	YES

Go to step 6.


	NO

Replace the passenger's air mix control motor.?

Passenger's air mix control motor internal resistance check (AMD-P AS, SENSOR COM):

Passenger's air mix control motor internal resistance check (AMD-P AS, SENSOR COM)

?1.	Reconnect the passenger's air mix control motor 7P connector.

?2.

Connect the battery power and ground to terminals A and B, then reverse the connections.

Terminal A	Climate control unit 32P connector No. 17 (LT GRN)
Terminal B	Climate control unit 32P connector No. 18 (BLU)

NOTE: Incorrectly applying power and ground to the motor will damage it. Follow the instructions carefully. When the motor stops running, disconnect battery power immediately.

?3.

Measure the resistance between test points 1 and 2.

Test condition	IG LOCK (0) or OFF mode
Test condition	Climate control unit 32P connector: disconnected
Test circuit	AMD-P AS, SENSOR COM
Test point 1	Climate control unit 32P connector No. 11 (PUR)
Test point 2	Climate control unit 32P connector No. 22 (BLU)

NOTE: Continuity between AMD-P AS and SENSOR COM may disappear when the motor is turned to the stop. Usually the climate control unit does not turn the motor to the stop.

Does resistance change between about 0?6 k?

1.8 k??


	YES

Replace the climate control unit.?


	NO

Replace the passenger's air mix control motor.?