GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 Jimmy - 2WD 🢒 Restraints 🢒 SIR 🢒 DTC B2356, B2366, or B2376

Circuit Description

Three of the seat adjuster motors are equipped with position sensors (transducers). They are the horizontal motor, front vertical motor and the rear vertical motor. The position sensors (transducers) are supplied with a 5-volt reference circuit and ground circuit from the memory seat module (MSM). The MSM receives a transducer input voltage from each position sensor (transducer) whenever a MSM output function is active.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B2356 Seat Front Vertical Position Sensor Circuit Range/Performance
    • DTC B2366 Rear Vertical Position Sensor Circuit Range/Performance
    • DTC B2376 Seat Horizontal Position Sensor Circuit Range/Performance

Conditions for Running the DTC

The MSM detects a switch signal active or a memory function request.

Conditions for Setting the DTC

The MSM detects the transducer input circuit under 0.75 volts or over 4.78 volts.

Action Taken When the DTC Sets

Memory functions for the motor that the DTC set for will be disabled as long as the fault is current.

Conditions for Clearing the DTC
    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present the DTC will be a history status code.
    • The history DTC will be cleared after 100 error free ignition cycles, or by using the scan tool clearing DTCs feature.

Test Description

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

  1. Tests for the proper operation of the circuit in the low voltage range.

    2.

  2. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.

    3.

  3. Tests for a short to voltage in the 5-volt reference circuit.

    4.

  4. Tests for a high resistance or an open in the low reference circuit.

Step

Action

Values

Yes

No

Schematic Reference: Driver Seat Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. With the scan tool, observe the Position Sensor parameter in the memory seat module (MSM) data list.

Does the scan tool indicate that the Position Sensor parameter is within the specified range?

0.75-4.7 V

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

Go to Step 3

3

  1. Disconnect the position sensor.
  2. With a scan tool, observe the Position Sensor parameter.

Does the scan tool indicate that the Position Sensor parameter is less than the specified value?

0.75 V

Go to Step 4

Go to Step 10

4

  1. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the position sensor and the transducer input circuit of the position sensor.
  2. With a scan tool, observe the Position Sensor parameter.

Does the scan tool indicate that the Position Sensor parameter is greater than the specified value?

4.75 V

Go to Step 5

Go to Step 8

5

  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5-volt reference circuit of the position sensor and the ground circuit of the position sensor.

Does the voltage measure less than the specified value?

5 V

Go to Step 6

Go to Step 7

6

  1. Disconnect the negative battery cable.
  2. Measure the resistance from the ground circuit of the position sensor to a good ground.

Does the resistance measure less than the specified value?

5 ohms

Go to Step 12

Go to Step 11

7

Test the 5-volt reference circuit of the position sensor 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 16

Go to Step 13

8

Test the 5-volt reference circuit of the position sensor for a short to ground, 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 16

Go to Step 9

9

Test the transducer input circuit of the position sensor for a short to ground, 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 16

Go to Step 13

10

Test the transducer input circuit of the position sensor 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 16

Go to Step 13

11
  1. Disconnect the MSM.
  2. Test the ground circuit of the position 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 16

Go to Step 13

12

Inspect for poor connections at the harness connector of the position 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 16

Go to Step 14

13

Inspect for poor connections at the harness connector of the 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 16

Go to Step 15

14

Replace the position sensor (transducer).

Did you complete the replacement?

--

Go to Step 16

--

15

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

Did you complete the replacement?

--

Go to Step 16

--

16
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the system within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK