DTC Troubleshooting: B1220 (56)
DTC B1220 or DTC indicator 56 : 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.
DTC Description
DTC
B1220 A Short in the recirculation control motor circuit
DTC (AC)
1.
Problem verification:
Problem verification
?1.
Clear the DTC with the HDS.
Clear DTCs
?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.
?4.
Check for DTCs.
DTC Description
DTC
B1220 A short in the recirculation control motor circuit
Is DTC B1220 or 56 indicated?
Intermittent failure. Check for loose wires or poor connections on the recirculation control motor circuit.?
2.
Open wire check (S 5V/S5V line):
Open wire check (S 5V/S5V line)
?1.
Turn the ignition switch to LOCK (0), press the engine start/stop button to select the OFF mode.
?2.
Disconnect the following connectors.
?3.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
Climate control unit 32P connector: disconnected
Recirculation control motor 7P connector: disconnected
Test circuit
S 5V/S5V
Test point 1
Climate control unit 32P connector No. 24 (BLK)
Test point 2
Recirculation control motor 7P connector No. 3 (BLK)
Is there continuity?
The S 5V/S5V wire is not open. Go to step 3.
Repair an open in the wire between the climate control unit and the recirculation control motor.?
3.
Shorted wire check (RFD-P/FRD-P line to SENSOR COM/SENS-COM line):
Shorted wire check (RFD-P/FRD-P 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
Recirculation control motor 7P connector: disconnected
Test circuit
RFD-P, SENSOR COM
Test point 1
Climate control unit 32P connector No. 22 (BLU)
Test point 2
Climate control unit 32P connector No. 28 (WHT)
Is there continuity?
Repair a short in the wires between the climate control unit and the recirculation control motor.?
The RFD-P/FRD-P wire to SENSOR COM/SENS-COM wire are not shorted. Go to step 4.
4.
Shorted wire check (RFD-P/FRD-P line):
Shorted wire check (RFD-P/FRD-P 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
Recirculation control motor 7P connector: disconnected
Test circuit
RFD-P
Test point 1
Climate control unit 32P connector No. 28. (WHT)
Test point 2
Body ground
Is there continuity?
Repair a short to body ground in the wire between the climate control unit and the recirculation control motor.?
The RFD-P/FRD-P wire is OK. Go to step 5.
5.
Recirculation control motor internal resistance check (S5V and SENS-COM):
Recirculation 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
Recirculation control motor 7P connector: disconnected
Test circuit
S5V, SENS-COM
Test point 1
Recirculation control motor No. 1
Test point 2
Recirculation control motor No. 3
Is the resistance 6 k?
1.8 k??
6.
Recirculation control motor internal resistance check (RFD-P and SENSER COM):
Recirculation control motor internal resistance check (RFD-P and SENSER COM)
?2.
Connect the battery power and ground to terminals A and B, then reverse the connections.
Terminal A
Climate control unit 32P connector No. 19 (ORN)
Terminal B
Climate control unit 32P connector No. 20 (PUR)
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
Climate control unit 32P connector: disconnected
Test circuit
RFD-P, SENSOR COM
Test point 1
Climate control unit 32P connector No. 22 (BLU)
Test point 2
Climate control unit 32P connector No. 28 (WHT)
NOTE: Continuity between RFD-P 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??