Diagnostic Test

WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Heated Seat Module (HSM) DTCs and record on the repair order.
2. With the scan tool, erase HSM DTCs.
3. Turn the ignition off.
4. Start the Engine.
5. Turn the Heated Seat on.
6. With the scan tool, read HSM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Go To 6
CHECK THE (P688) RIGHT FRONT HEATED SEAT TEMP SENSE CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the HSM C2 harness connector.
3. Disconnect the HSM C3 harness connector (if equipped with rear heated seats).
4. Start the Engine.
5. Measure the voltage between ground and the (P688) Right Front Heated Seat Temp Sense circuit at the HSM C2 harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (P688) Right Front Heated Seat Temp Sense circuit or the (P968) Heated Seat Sensor Return circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3

CHECK THE SEAT TEMPERATURE SENSOR RESISTANCE

Temperature Sensor Resistance
°C	°F	Nominal (Ohms)	Minimum (Ohms)	Maximum (Ohms)
-40	-40	336, 500	306, 959	366, 042
-35	-31	242, 589	222, 163	263, 015
-30	-22	177, 000	162, 706	191, 294
-25	-13	130, 370	120, 273	140, 467
-20	-4	97, 070	89, 860	104, 280
-15	5	72, 929	67, 735	78, 124
-10	14	55, 330	51, 551	59, 108
-5	23	42, 315	39, 545	45, 085
0	32	32, 650	30, 601	34, 699
5	41	25, 388	23, 861	26, 914
10	50	19, 900	18, 754	21, 046
15	59	15, 708	14, 842	16, 574
20	68	12, 490	11, 831	13, 149
25	77	10, 000	9, 500	10, 500
30	86	8, 057	7, 632	8, 482
35	95	6, 531	6, 173	6, 889
40	104	5, 327	5, 024	5, 630
45	113	4369	4111	4626
50	122	3603	3384	3822
55	131	2986	2799	3174
60	140	2488	2327	2649
65	149	2083	1945	2221
70	158	1752	1633	1871
75	167	1, 481	1, 378	1, 585
80	176	1, 258	1, 168	1, 348
85	185	1, 072	994.2	1, 151
90	194	917.7	849.4	986.0
95	203	788.5	728.6	848.4
100	212	680.0	627.4	732.6

Turn the ignition off.
Measure the resistance between the (P688) Right Front Heated Seat Temp Sense circuit and the (P968) Heated Seat Sensor Return circuit at the HSM C2 harness connector.
Compare the measured resistance to the Temperature Sensor Resistance chart.
Is the resistance within the specifications listed in the chart?

Yes
- Replace the Heated Seat Module (HSM) in accordance with the Service Information. Refer to MODULE, HEATED SEAT, REMOVAL .
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
No
- Go To 4

CHECK THE (P688) RIGHT FRONT HEATED SEAT TEMP SENSE CIRCUIT OR AN OPEN
1. Disconnect the Right Seat Cushion Heater harness connector.
2. Measure the resistance of the (P688) Right Front Heated Seat Temp Sense circuit between the HSM C2 connector and the Right Front Seat Cushion Heater connector (harness side).
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (P688) Right Front Heated Seat Temp Sense circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (P968) HEATED SEAT SENSOR RETURN CIRCUIT FOR AN OPEN
1. Measure the resistance of the (P968) Heated Seat Sensor Return circuit between the HSM C2 harness connector and the Right Front Seat Cushion Heater harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Replace the Right Front Seat Temperature Sensor (part of the Right Front Seat Cushion Heater Element) in accordance with the Service Information. Refer to PAD, HEATER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repair the (P968) Heated Seat Sensor Return circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle the wiring and connectors while checking for shorted and open circuits. Attempt to reproduce the condition by adjusting the seat(s).
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Verify the seat wiring harness is routed correctly to the Heated Seat Module (HSM).
4. Check Service Bulletins for any possible causes that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test complete.