GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Blazer - 4WD - RHD 🢒 DTC 🢒 DTC B1826 Driver Recline Sensor CKT Performance

Circuit Description

The memory seat module controls the seat recliner motor power and ground through CKT 76 (DK BLU) and CKT 77 (DK BLU). The memory seat module also senses the seat recliner motor position through a hall sensor within the motor through CKT 570 (BLK/WHT) while utilizing CKT 569 (BLK/WHT) as a sensor ground.

Conditions for Setting the DTC

The DTC will set if the memory seat module detects through the hall sensor that the recline motor is not responding to the memory seat module commands due to the following:

    • an open circuit
    • shorted to ground circuit
    • shorted to power circuit
    • inoperative motor

Conditions for Clearing the MIL/DTC
    • A history DTC will clear after 100 consecutive fault free ignition cycles.
    • Use a scan tool in order to clear history and current DTCs.

Diagnostic Aids

One or more of the following conditions could be the cause of an intermittent failure:

    • A poor connection
    • A break in the wire insulation that exposes the internal wire
    • A wire broken inside the insulation

Test Description

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

  1. This step inspects the current DTC.

    2.

  2. This step inspects the wiring between seat recliner motor and memory seat module for open circuits.

    3.

  3. This step repairs open(s) in the wiring between the seat recliner motor and memory seat module.

    4.

  4. This step inspects the wiring between the seat recliner motor and memory seat module for short(s) to ground.

    5.

  5. This step repairs short(s) to ground in the wiring between the seat recliner motor and memory seat module.

    6.

  6. This step determines proper memory seat module operation.

    7.

  7. This step relaces the defective seat recliner motor.

    8.

  8. This step replaces the defective memory seat module.

    9.

  9. This step determines that there is possibly an intermittent problem and refers back to the Memory Seat System Check.

Step

Action

Value(s)

Yes

No

1

Have you perform the Memory Seat System Check?

--

Go to Step 2

Go to Memory Seats System Check

2

  1. Turn ignition to the OFF position.
  2. Install scan tool.
  3. Turn ignition to the RUN position.
  4. Using scan tool, check for DTCs.

Is DTC B1826 set as a current DTC?

--

Go to Step 3

Go to Step 10

3

Using A Digital Multimeter (DMM), check the continuity of each of the following circuits from the memory seat module to the seat recliner motor.

    • CKT 76 (DK BLU)
    • CKT 77 (DK BLU)
    • CKT 569 (BLK/WHT)
    • CKT 570 (BLK/WHT

Is there continuity on all circuits?

--

Go to Step 5

Go to Step 4

4

Locate and repair the open circuit(s).

Is the repair complete?

--

Go to Memory Seats System Check

--

5

  1. Disconnect the memory seat module
  2. Use a DMM to check for continuity to ground each of the following circuits at the memory seat module connector:
    3. • CKT 76 (DK BLU)
    • CKT 77 (DK BLU)
    • CKT 569 (BLK/WHT)
    • CKT 570 (BLK/WHT

Is there continuity on all circuits?

--

Go to Step 6

Go to Step 7

6

Locate and repair the short(s) to ground.

Is the repair complete?

--

Go to Memory Seats System Check

--

7

  1. Reconnect the memory seat module connector
  2. Disconnect the seat recliner motor and connect a test lamp between the CKT 76 and CKT 77 terminals of the connector

Does the lamp light when the recliner switch is in the FORWARD and BACK positions?

--

Go to Step 8

Go to Step 9

8

Replace the recliner motor.

Is the repair Complete?

--

Go to Memory Seats System Check

--

9

Replace the memory seat module.

Is the repair Complete?

--

Go to Memory Seats System Check

--

10

Disregard the history DTC B1826.

Has the step been completed?

--

Go to Diagnostic System Check

--