GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2002 🢒 Yukon - 2WD 🢒 Body and Accessories 🢒 Seats 🢒 DTC B1826

Circuit Description

The recline seat motor is equipped with a potentiometer type position sensor used by the memory seat module to determine the seat recline position. The recline motor position sensor is supplied with 5-volt reference and ground circuits from the memory seat module. The position sensor signal circuit is supplied 5-volts through a resistor then monitored within the memory seat module. The signal voltage monitored by the memory seat module ranges from 0.39 - 4.58 volts and is determined by the wiper location on the resistor within the recline motor position sensor. The recline motor position sensor circuit voltage level is used by the memory seat module to determine the seat recline position when storing or recalling memory seat position settings.

Conditions for Running the DTC

The system voltage must be between 9.0 and 16.0 volts.

Conditions for Setting the DTC

The recline motor position sensor circuit voltage level to the memory seat module is not within the 0.39 - 4.58 volt range.

Action Taken When the DTC Sets

The recline motor memory functions will be disabled for 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 signal circuit in the high voltage range.

    2.

  2. Tests for the proper operation of the signal 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.

    3.

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

Step

Action

Values

Yes

No

Schematic Reference: Memory Seats Schematics

1

Did you perform the Power Seat Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2
  1. Install a scan tool.
  2. With a scan tool, observe the recline position sensor parameter in the data list for the memory seat module.

Is the recline position sensor parameter within the specified range?

..39-4.58 V

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3
  1. Disconnect the recline position sensor.
  2. With a scan tool, observe the recline position sensor parameter.

Is the recline position sensor parameter greater than the specified value?

4.58 V

Go to Step 4

Go to Step 8

4
  1. Connect a 3-ampere fused jumper wire between the signal circuit of the recline position sensor and the low reference circuit of the recline position sensor.
  2. With a scan tool, observe the recline position sensor parameter.

Is the recline position sensor parameter less than the specified value?

.39 V

Go to Step 5

Go to Step 9

5
  1. Disconnect the fused jumper wire.
  2. Connect a 3-ampere fused jumper wire between the 5-volt reference circuit of the recline position sensor and the signal circuit of the recline position sensor.
  3. With a scan tool, observe the recline position sensor parameter.

Is the recline position sensor parameter greater than the specified value?

4.58 V

Go to Step 7

Go to Step 6

6

Test the 5-volt reference circuit of the recline position sensor for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

7

Test the 5-volt reference circuit of the recline position sensor for one of the following conditions:

    • A short to voltage
    • A high resistance
    • An open

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

8

Test the signal circuit of the recline position sensor for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

9

Test the signal circuit of the recline position sensor for one of the following conditions:

    • A short to voltage
    • A high resistance
    • An open

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Test the low reference circuit of the recline position sensor for one of the following conditions:

    • A high resistance
    • An open

Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the recline position sensor . Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 13

12

Inspect for poor connections at the harness connector of the memory seat module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Replace the recline adjuster motor. Refer to Front Seat Adjuster Motor Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

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

Did you complete the replacement?

--

Go to Step 15

--

15
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the system in order to verify the repair.

Does the DTC reset?

--

Go to Step 2

System OK