GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 Eldorado 🢒 DTC 🢒 DTC B0846

Circuit Description

The memory seat module (MSM) supplies a 5 volt reference voltage via the 5 volt reference circuit to all of the seat position sensors.

Conditions for Setting the DTC

The 5 volt reference voltage falls out of the range of 4.6-5.2 volts.

Action Taken When the DTC Sets
    • All memory recall commands are ignored.
    • The MSM will individually respond to all switch inputs.

Conditions for Clearing the DTC

The DTC automatically clears when the 5 volt reference voltage is within a valid operating range.

Test Description

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

  1. This step tests for an open or short to ground in the 5 volt reference circuit.

    2.

  2. This step tests for a short to battery positive voltage (B+) in 5 volt reference circuit.

Step

Action

Value(s)

Yes

No

Schematic Reference: Memory Seats Schematics

1

Did you perform the Diagnostic System Check - Power Seat Systems?

--

Go to Step  2

Go to Diagnostic System Check - Power Seat Systems

2

  1. Turn OFF the ignition.
  2. Disconnect the seat front vertical position sensor harness connector.
  3. Measure the voltage from the 5 volt reference circuit of the sensor connector to a good ground.

Does the voltage measure near the specified value?

0 V

Go to Step  4

Go to Step  3

3

Does the voltage measure near the specified value?

12 V

Go to Step  6

Go to Step  5

4

Test the 5 volt reference circuit of the seat position sensors for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step  8

Go to Step  5

5

Inspect for poor connections at the harness connector of the memory seat module (MSM). 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  8

Go to Step  7

6

Repair the short to voltage in the 5 volt reference circuit of the seat position sensors. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step  8

--

7

Replace the memory seat module (MSM). Refer to Memory Seat Control Module Replacement .

Did you complete the repair?

--

Go to Step  8

--

8
  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