GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Blazer - 4WD - RHD 🢒 DTC 🢒 DTC B2356 Driver Front Vert. Sensor Performance

Circuit Description

The memory seat module monitors the seat front height motor position through the seat front height transducer CKT 557 (ORN/BLK). The memory seat module also sends a reference voltage on CKT 569 (RED) and provides a sensor ground (BLK).

Conditions for Setting the DTC

The DTC will set if the memory seat module detects that the seat front height sensor output voltage is either too high or too low due to the following:

    • an open circuit.
    • shorted to ground circuit.
    • shorted to power circuit.
    • defective seat height transducer.

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 the seat front height transducer and the memory seat module for open circuits.

    3.

  3. This step repairs open(s) in the wiring between the seat front height transducer and memory seat module.

    4.

  4. This step inspects the wiring between the seat front height transducer and the memory seat module for short(s) to ground.

    5.

  5. This step repairs short(s) to ground in the wiring between the seat front height transducer and memory seat module.

    6.

  6. This step determines proper memory seat module operation.

    7.

  7. This step relaces the defective seat front height transducer.

    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 B2356 set as a current DTC?

--

Go to Step 3

Go to Step 10

3

  1. Disconnect the memory seat module
  2. Use a digital multimeter (DMM) to check the continuity of each of the following circuits between the memory seat module connector and the seat front height transducer connector.
    3. • CKT 569 (RED)
    • CKT 557 (ORN/BLK)
    • CKT 569 (BLK)

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 digital multimeter (DMM) to check the continuity to ground of each of the following circuits at the memory seat module connector.
    3. • CKT 569 (RED)
    • CKT 557 (ORN/BLK)
    • CKT 569 (BLK)

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 front height transducer and connect a DMM between the CKT 569 (RED) and CKT 569 (BLK) terminals of the connector.

Does the DMM show the specified value?

5 volts

Go to Step 8

Go to Step 9

8

Replace the seat front height transducer.

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 B2356.

Has the step been completed?

--

Go to Diagnostic System Check

--