Front Seat Heater Control Unit Input Test
NOTE: Before testing, make sure the No. B5 (10 A), No. B9 (10 A), and No. B32 (20 A) fuses in the under-dash fuse/relay box are OK.

1.
2.
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 3.

3.
With the connector still disconnected, 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 4.

Cavity
Wire
Test condition
Test: Desired result
Possible cause if desired result is not obtained
13
•
7
ORN
•
YEL
Under all conditions
Check for continuity between terminals No. 13 and No. 7:
There should be continuity.
Faulty driver's seat cushion heater
An open or high resistance in the wire
12
•
6
GRN
•
BLU
Under all conditions
Check for continuity between terminals No. 12 and No. 6:
There should be continuity.
Faulty front passenger's seat cushion heater
An open or high resistance in the wire

4.
Reconnect the 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 front seat heater control unit.

Cavity
Wire
Test condition
Test: Desired result
Possible cause if desired result is not obtained
2
LT GRN
Vehicle ON mode
Measure the voltage to ground:
There should be battery voltage.
Blown No. B32 (20 A) fuse in the under-dash fuse/relay box
Faulty front seat heater relay circuit
An open or high resistance in the wire
9
RED
Vehicle ON mode
Measure the voltage to ground:
There should be battery voltage.
Blown No. B5 (10 A) fuse in the under-dash fuse/relay box
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 (G602)
An open or high resistance in the ground wire
1
GRN
Vehicle ON mode, driver's seat heater operation
Measure the voltage to ground:
There should be battery voltage.
Faulty driver's seat heater
Poor ground (G601) or an open in the ground wire
An open or high resistance in the wire
3
RED
Vehicle ON mode, front passenger's seat heater operation
Measure the voltage to ground:
There should be battery voltage.
Faulty front passenger's seat heater
Poor ground (G602) or an open in the ground wire
An open or high resistance in the wire