Rear Seat Heater Control Unit Input Test
NOTE:
Make sure the fuses associated with the system is OK.
Before testing, do the seat heater control unit self-diagnostic function, and make sure the seat heater function is OK.

1.
Turn the vehicle to the OFF (LOCK) mode.

2.
Disconnect the rear seat heater control unit 24P connector.
Rear Seat Heater Control Unit 24P Connector (female terminals)

3.
Inspect the connector and socket terminals to be sure they are all making good contact:
If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
If the terminals look OK, go to step 4.

4.
Reconnect the rear seat heater control unit 24P connector, and do the following input tests:
If any test indicates a problem, find and correct the cause, then recheck the system.
If all the input tests prove OK, go to step 5.

Cavity
Wire
Test condition
Test: Desired result
Possible cause if desired result is not obtained
2
WHT
Vehicle ON mode
Measure the voltage to ground:
There should be battery voltage.
Faulty rear seat heater relay circuit
An open or high resistance in the wire
14
RED
Vehicle ON mode
Measure the voltage to ground:
There should be battery voltage.
An open or high resistance in the wire
4
BLK
In all power modes
Measure the voltage to ground:
There should be less than 0.2 V.
Poor ground (G505)
An open or high resistance in the ground wire
1
PNK
Vehicle ON mode, left rear seat heater ON mode
Measure the voltage to ground:
There should be battery voltage.
Faulty left rear seat heater
Poor ground (G505) or an open in the ground wire
An open or high resistance in the wire
3
LT GRN
Vehicle ON mode, right rear seat heater ON mode
Measure the voltage to ground:
There should be battery voltage.
Faulty right rear seat heater
Poor ground (G505) or an open in the ground wire
An open or high resistance in the wire

5.
Turn the vehicle to the OFF (LOCK) mode.

6.
Disconnect the rear seat heater control unit 24P connector, and do the following input tests:
If any test indicates a problem, find and correct the cause, then recheck the system.
If all the input tests prove OK, replace the rear seat heater control unit.

Cavity
Wire
Test condition
Test: Desired result
Possible cause if desired result is not obtained
15
GRN
Disconnect the front seat heater control unit 24P connector
Check for continuity between terminal No. 15 and front seat heater control unit 24P connector terminal No. 15:
There should be continuity.
An open or high resistance in the wire
Check for continuity to ground:
There should be no continuity.
A short to ground in the wire
12
TAN
Under all conditions
Check for continuity between terminals No. 12 and No. 22:
There should be continuity.
Faulty left rear seat cushion heater
An open or high resistance in the wire
22
LT BLU
13
PNK
Under all conditions
Check for continuity between terminals No. 13 and No. 23:
There should be continuity.
Faulty right rear seat cushion heater
An open or high resistance in the wire
23
YEL