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Test Description

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  If an active DTC is set, the BCM will turn off the heated seat relay not allowing for an accurate test of the relay. By cycling the ignition switch, the BCM turns off the active DTC allowing for an accurate test.
  2. 3:  This test determines the functionality of the heated seat relay.
  3. 22:  This test verifies the repair.
DTC B1920 or B2165

Step Action Value(s) Yes No
Schematic Reference: Driver Seat Schematics  or Passenger Seat Schematics 
Connector End View Reference: Power Seat Systems Connector End Views 
1 Did you perform the Diagnostic System Check - Power Seat Systems? - Go to Step 2  Go to Diagnostic System Check - Power Seat Systems 
  1. Turn Off the ignition.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a test lamp from the heated seat element supply voltage circuit of the heated seat relay to a good ground.
  4. Turn On the heated seat to the high heat position.
Does the test lamp illuminate?
- Go to Step 4  Go to Step 3 
  1. Disconnect the heated seat relay.
  2. Connect a test lamp from the battery positive voltage circuit of the relay connector to a good ground.
Does the test lamp illuminate?
- Go to Step 13  Go to Step 18 
4
  1. Disconnect the heated seat relay.
  2. Measure the resistance from the heated seat element supply voltage circuit of the relay connector to a good ground.
Does the resistance measure less than the specified value?
5 Ω Go to Step 7  Go to Step 5 
5
  1. Disconnect the seat cushion heater element.
  2. Measure the resistance across the circuits of the seat cushion heater element harness connector.
Does the resistance measure less than the specified value?
5 Ω Go to Step 6  Go to Step 14 
6
  1. Disconnect the seat back heater element.
  2. Measure the resistance across the circuits of the seat back heater element harness connector.
Does the resistance measure less than the specified value?
5 Ω Go to Step 10  Go to Step 15 
7
IMPORTANT: 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.
  1. Disconnect the body control module connector C2.
  2. Measure the resistance between the temperature sensor signal circuit and the sensor low reference circuit of the BCM connector.
Does the resistance measure within the specified range?
535 Ω-168,000 Ω Go to Step 12  Go to Step 8 
8 Test the heated seat temperature sensor signal circuit and the temperature sensor low reference circuit between the BCM and the temperature sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 22  Go to Step 9 
9 Test the heated seat temperature sensor signal circuit and between the BCM and the temperature sensor for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 22  Go to Step 14 
10 Test the heated seat element supply voltage circuit between the heated seat relay and the seat cushion heating element for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 22  Go to Step 11 
11 Test the heated seat element supply voltage circuit between the seat cushion heating element and the seat back heating element for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 22  Go to Step 17 
12 Test the heated seat element supply voltage circuit between the seat cushion heating element and the seat back heating element 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 22  Go to Step 16 
13 Inspect for poor connections at the harness connector of the heated seat relay. 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 22  Go to Step 19 
14 Inspect for poor connections at the harness connector of the heated seat cushion heating element/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 22  Go to Step 20 
15 Inspect for poor connections at the harness connector of the heated seat back heating element. 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 22  Go to Step 20 
16 Inspect for poor connections at the harness connector of the body 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 22  Go to Step 21 
17 Repair the open in the ground circuit of the seat heating elements. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
- Go to Step 22  -
18 Repair the short to ground or open in the battery positive voltage circuit of the heated seat relay. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
- Go to Step 22  -
19 Replace the heated seat relay. Refer to Relay Replacement - Heated Seats - Front .
Did you complete the replacement?
- Go to Step 22  -
20 Replace the heated seat cushion heating element/temperature sensor or seat back heating element. Refer to Seat Back Heater Element Replacement - Front  and to Seat Cushion Heater Element Replacement - Front .
Did you complete the replacement?
- Go to Step 22  -
21
IMPORTANT: Perform the Programing/RPO Configuration for the replacement BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System.Did you complete the replacement?
- Go to Step 22  -
22 
  1. Clear the DTCs using the scan tool.
  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