GM Service Manual Online
For 1990-2009 cars only

Object Number: 261815  Size: MF
Body Control Module Components
Cell 50: Class Serial Data Line (1 of 2)
Handling ESD Sensitive Parts Notice
Cell 10: DRV MDL, PASS MDL, RRDR MDL, and ALDL Fuses

Circuit Description

Battery Positive Voltage (B+) is supplied to the LH Front Door Module (LFDM) at the LFDM connector C1, terminal 11, CKT 640 (ORN). The LFDM monitors this voltage to determine if it is within a valid operating range.

Conditions for Setting the DTC

The Battery Positive Voltage (B+) level rises above 15.5 volts for more than approximately 1.2 seconds.

Action Taken When the DTC Sets

    • Stores a DTC B1982 in the LFDM memory.
    • The LFDM will not respond to any manual or memory inputs when the voltage is greater than 16 volts
    • No driver warning message will be displayed for this DTC.
    • The LFDM switch failure and position sensor failure DTCs will not set while DTC B1982 is current.

Conditions for Clearing the DTC

    • The Battery Positive Voltage (B+) level falls below 15 volts for approximately 1.2 seconds.
    • Use the On-Boards clearing DTCs feature.
    • Use a scan tool.

Diagnostic Aids

This DTC may set when the vehicle is placed on a battery charger, on fast charge, for a long period of time.

Test Description

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

  1. Perform the Power Door System Diagnostic System Check before continuing with the diagnosis of this DTC.

  2. Checks that DTC was not set erroneously.

  3. Determines whether the malfunction is in the charging system or the LH Front Door Module (LFDM).

  4. Clear all DTCs after the repair procedure is complete.

DTC B1982 -- Source/Battery Voltage High

Step

Action

Value(s)

Yes

No

1

Was the Power Door System Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Power Door Systems

2

  1. Connect a scan tool.
  2. Clear the driver door module DTCs.
  3. Start the engine.

Does the DTC reset?

--

Go to Step 3

Go to Charging System Check in Engine Electrical

3

  1. Start the engine.
  2. Select Powertrain Engine DATA 1 (Ignition 1).

Is Ignition 1 voltage equal to or greater than the specified value?

15.5 V

Go to Charging System Check in Engine Electrical

Go to Step 4

4

Replace the LFDM. Refer to Door Control Module Replacement .

Is the LFDM replacement complete?

--

Go to Step 5

--

5

  1. Turn OFF the ignition switch.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition switch.
  4. Clear any DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing .

Are all DTCs cleared?

--

Go to Diagnostic System Check - Power Door Systems

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