Circuit Description
The heated seat temperature sensor that set this DTC is located in the seat cushion just under the seat cover with the seat heating element. The body control module (BCM) supplies a 10-volt signal circuit and a low reference circuit to the sensor. The BCM monitors the voltage of the heated seat temperature sensor signal circuit to determine the temperature of the seat. The BCM will then cycle the heated seat relay ON and OFF in order to maintain the desired seat temperature based on the voltage feedback from the temperature sensor.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1925 Seat Heater Sensor Circuit |
| • | DTC B2170 Seat Heater Sensor |
Conditions for Running the DTC
| • | The BCM must be powered and cannot have B1327, Battery Voltage Low, as an active DTC for this DTC to set. |
| • | The heated seat system must be active. |
| • | The module voltage must be 9-16 volts. |
Conditions for Setting the DTC
The BCM detects that the signal circuit of the temperature sensor signal circuit is either too high or too low.
Action Taken When the DTC Sets
| • | The BCM will turn OFF the heated seat operation. |
| • | Current and history codes are set. |
Conditions for Clearing the DTC
The current DTC will clear whenever the diagnostic feedback to the BCM indicates that the fault no longer exists and the ignition switch is turned OFF and then back ON again.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests for the proper operation of the circuit in the high voltage range.
-
This step tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens upon performing this test, the signal circuit has a short to voltage.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Driver Seat Schematics or Passenger Seat Schematics Connector End View Reference: Power Seat Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the voltage measure near the specified value? | 10 V | Go to Step 3 | Go to Step 5 |
Measure the voltage between the temperature sensor signal circuit and the temperature sensor low reference circuit. Does the voltage measure near the specified value? | 10 V | Go to Step 4 | Go to Step 7 | |
Measure the resistance between the temperature sensor signal circuit and the temperature sensor low reference circuit. Does the resistance measure within the specified range? | 535-168,000 ohms | Go to Step 9 | Go to Step 8 | |
5 | Test the temperature sensor signal circuit between the body control module (BCM) and the sensor connector for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 6 |
6 | Test the temperature sensor signal circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
7 | Test the low reference circuit of the temperature sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 |
8 | Test the temperature sensor signal circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 |
9 | Test the temperature sensor signal circuit between the sensor connector and the temperature sensor for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 11 | |
10 | Inspect for poor connections at the harness connector of the heated seat temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
11 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 |
12 | Replace the heated seat temperature sensor/heater element assembly. Refer to Driver Seat and Passenger Seat Back Cushion Heater Replacement and Driver Seat and Passenger Seat Cushion Heater Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
