Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if the rear heated seat system is totally inoperative.
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This step determines if the seat is completely inoperative, or if just one of the 2 seat cushions is inoperative.
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This step determines if the temperature sensor is open or if only one of the sensor circuits is open. A short to battery voltage in the sensor signal circuit will open the sensor.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Rear Seat Schematics Connector End View Reference: Component Connector End Views DEFINITION: This test assumes that load shed level 1 or 2 heated seats is not enabled, and that heated seats inhibit switch is OFF. | ||||
1 | Did you review the heated seat operation and perform the necessary inspection? | -- | Go to Step 2 | Go to Symptoms - Seats |
2 | Verify that the Heated Seat Inoperative - Rear complaint is present. Does the heated seat system operate as described in the system description and operation? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
Are both the left and right rear heated seats Inoperative? | -- | Go to Step 5 | Go to Step 4 | |
Is the seat back inoperative? | -- | Go to Step 11 | Go to Step 8 | |
5 |
Does the voltage measure within the specified range? | 10-16 V | Go to Step 6 | Go to Step 23 |
6 | Measure the voltage from the ignition 3 voltage circuit of the heated seat module to the ground circuit of the heated seat module. Does the voltage measure within the specified range? | 10-16 V | Go to Step 7 | Go to Step 24 |
7 |
Does the voltage measure within the specified range? | 10-16 V | Go to Step 9 | Go to Step 13 |
8 |
Does the measured voltage change state? | -- | Go to Step 10 | Go to Step 14 |
9 |
Does the resistance measure less than the specified value for both seats? | 5 Ω | Go to Step 15 | Go to Step 25 |
10 |
Note: If the resistance is measured with the seat still warm, the resistance may vary outside of the specified range since the thermistor resistance varies with temperature. Measure the resistance between the signal circuit of the temperature sensor and the low reference circuit of the temperature sensor. Does the resistance measure within the specified range? | 850 Ω - 1150 K Ω | Go to Step 12 | Go to Step 16 |
11 |
Is the resistance value less than the specified value? | 10 Ω | Go to Step 26 | Go to Step 22 |
12 |
Is the resistance value less than the specified value? | 10 Ω | Go to Step 17 | Go to Step 21 |
13 | Test the voltage supply circuit of the heated seat switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 20 |
14 | Test the heated seat switch signal circuit between the heated seat switch and the heated seat module for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 19 |
15 | Test the heating element supply voltage circuits and element control circuits to both rear seats for a short to voltage. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 20 |
Test the temperature sensor signal circuit and the sensor low reference circuit between the heated seat module and the temperature sensor for a short to battery voltage and an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 21 | |
17 | Test the element supply voltage circuit and the element control circuit between the heated seat module and the seat heating elements for an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 18 |
18 | Test the temperature sensor signal circuit between the heated seat module and the temperature sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 20 |
19 | Inspect for poor connections at the harness connector of the heated seat switch. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 27 |
20 | Inspect for poor connections at the harness connector of the heated seat module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 28 |
21 | Inspect for poor connections at the harness connector of the seat cushion heating element and temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 29 |
22 | Inspect for poor connections at the harness connector of the seat back heating element. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 31 | Go to Step 30 |
23 | Repair the short to ground or open in the IGN 3 voltage circuit of the heated seat module. Refer to Wiring Repairs. Is the trouble corrected? | -- | Go to Step 31 | -- |
24 | Repair the open in the ground circuit of the heated seat module. Refer to Wiring Repairs. Is the trouble corrected? | -- | Go to Step 31 | -- |
25 | Repair the open in the supply voltage circuit or the control circuit of the seat heating elements. Refer to Wiring Repairs. Is the trouble corrected? | -- | Go to Step 31 | -- |
26 | Repair the high resistance or open in the element supply voltage circuit or the element control circuit between the splice and the seat back heating element. Refer to Circuit Testing and Wiring Repairs. Is the trouble corrected? | -- | Go to Step 31 | -- |
27 | Replace the rear heated seat switch. Refer to Auxiliary Heater and Air Conditioning Control Replacement. Have you finished the replacement? | -- | Go to Step 31 | -- |
28 | Replace the rear heated seat module. Refer to Control Module References for replacement, setup, and programming. Have you finished the replacement? | -- | Go to Step 31 | -- |
29 | Replace the seat cushion heating element/temperature sensor. Refer to Heated Seat Always On. Have you finished the replacement? | -- | Go to Step 31 | -- |
30 | Replace the seat back heating element. Refer to Rear Seat Back Ventilation Heating and Cooling Blower Replacement. Have you finished the replacement? | -- | Go to Step 31 | -- |
31 | Operate the system to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
