QuestionQUESTION: I just purchased a 2003 Montana Luxury Van. It has heated seats. The passenger seat does not heat up. I did not see any wires disconnected. I was sitting in the seat when I turned it on and I was wearing the seat belt. If you could offer any suggestions, help me find a schematic or troubleshooting procedure that would great!
Thanks,
Tim
ANSWER: Hi
I would first check fuses etc...
If all that checks out, All I can send you is this diagnostic sheet.
I CANNOT send schematics, sorry
For schematics, go to your lacal GM dealership and have them print out SI Doc. ID 846923.
I Hope this helps
Pawl
Step
Action
Value(s)
Yes
No
2
Turn the ignition ON.
Turn the heated seat switch ON.
Does the heated seat operate properly?
--
Go to Testing for Intermittent and Poor Connections in Wiring Systems
Go to Step 3
3
Does the heated seat switch indicator illuminate when the switch is turned ON?
--
Go to Step 6
Go to Step 4
4
Test the heated seat switch ignition voltage supply circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 5
5
Test the heated seat switch ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 11
6
Disconnect the heated seat cushion 4-way connector.
Connect a test lamp from the heated seat switch signal circuit terminal in the harness connector to ground.
Turn the ignition ON.
Turn the heated seat switch ON.
Does the test lamp illuminate?
--
Go to Step 7
Go to Step 10
7
Test the heated seat battery positive voltage supply circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 8
8
Test the heated seat ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 9
9
Disconnect the heated seat back element connector.
Measure the resistance of the heated seat back element. Refer to Circuit Testing in Wiring Systems.
Is the resistance within the specified values?
0.5-2 ohms
Go to Step 15
Go to Step 13
10
Test the heated seat switch signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 11
11
Inspect for poor connections at the heated seat switch. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 12
12
Replace the heated seat switch.
Is the repair complete?
--
Go to Step 17
--
13
Inspect for poor connections at the heated seat back element connector. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 14
14
Replace the heated seat back element. Refer to Seat Back Heater Element Replacement - Front .
Is the repair complete?
--
Go to Step 17
--
15
Inspect for poor connections at the heated seat cushion 4 way connector. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 17
Go to Step 16
16
Replace the heated seat cushion element. Refer to Seat Cushion Heater Element Replacement - Front .
Is the repair complete?
--
Go to Step 17
--
17
Operate the system in order to verify the repair.
Did you correct the condition?
--
System OK
Go to Step 3
---------- FOLLOW-UP ----------
QUESTION: Pawl,
Thank you very much for the dianostic. I have done some research on this subjuct and came accross a couple issues that after reading your dianostic, I believe may be irrelevent. So, I will run them by you.
Is the seatbelt buckle part of the circuit? Some blogs I have read say the seatbelt needs to be buckled in order for the seat heater to work.
Another post I read somewhere mentioned that a person needs to be sitting in the seat in order for it to work?
Since the diagnostic mentions neither of these, I assume they are myths but, I thought I would double check with you.
Lastly, you mentioned checking the fuses. Is the driver's seat on a separate fuse from the passenger's seat?
Thanks again for your help. As soon as the temp here gets above 20 I'll get out there and check it! LOL
Tim
AnswerHi
From schematics and circuit description, these vehicles DO NOT have a passanger presence system.
Also seat belt will have no effect on heated seats.
I'd beg to ask blogs where their info comes from? Mine is from printed GM SI (General Motors Service Information) which we use in the dealership.
The fuse is in the IP fuse box, (Inside box) and is the DRL/HVAC?TEMP/HTD ST fuse, 10A.
The fuse feeds the switch, which operates both heated seat assemblies.
There is a looks like a fuse at each seat the manual calls it the PTC.... Has an Orange wire in and a yellow out.
I do not know what this is, but there is one at each seat.
Follow post back, if needed.
Pawl
