GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 DeVille 🢒 Body 🢒 Seats 🢒 DTC B1913 or B1918

Circuit Description

The heated seat mode and temperature switches are normal open. When the switch is pressed, it momentarily sends a 12 volt signal to the door control module. The door module then momentarily pulls the appropriate signal circuit of the heated seat module low. In response, the heated seat module activates the heated seat.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1913 Seat Heater Switch 1 Circuit High
    • DTC B1918 Seat Heater Switch 2 Circuit High

Conditions for Running the DTC

The door module must be powered and can not have B1327 - Battery Voltage Low or B1328 - Battery Voltage High set as an active DTC for this DTC to set.

Conditions for Setting the DTC

If the door module detects that a heated seat switch input circuit is active for 30 continuous seconds, the switch will be considered shorted and the DTC will set.

Action Taken When the DTC Sets

After the initial heated seat activation, no other heated seat switch activations shall be recognized as a result of this switch circuit being active.

Conditions for Clearing the DTC

The DTC automatically clears when the switch circuit setting the DTC is no longer active.

Test Description

The number below refers to the step number on the diagnostic table.

  1. Checks the existing state of the heated seat mode BACK ONLY switch by using the current state of the input parameter.

Step

Action

Yes

No

Schematic Reference: Driver Seat Schematics , Passenger Seat Schematics , and Rear Seat Schematics

Connector End View Reference: Power Seat Connector End Views or Power Door Systems Connector End Views in Doors

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the appropriate Heated Seat parameter in the appropriate Door Module Input data list.

Does the scan tool display OFF?

Go to Step 3

Go to Step 4

3
  1. Activate the suspect heated seat switch.
  2. With a scan tool, observe the appropriate Heated Seat parameter.

Does the suspect Heated Seat parameter change state?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4
  1. Turn OFF the ignition.
  2. Disconnect the heated seat switch connector.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the appropriate Heated seat parameter.

Does the scan tool display OFF?

Go to Step 7

Go to Step 5

5

Test the suspect switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step  6

6

Inspect for poor connections at the harness connector of the door control module. 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 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the heated seat switch. 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 10

Go to Step 9

8

Replace the door control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 10

--

9

Replace the heated seat switch. Refer to Rear Seat Heater Switch Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK