GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 LeSabre 🢒 Restraints 🢒 SIR 🢒 DTC B1390

Circuit Description

The dash integration module (DIM) has an internal battery voltage sensor and a reference voltage. The DIM compares these 2 voltages via the 2 battery positive voltage circuits every 300 milliseconds.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1390 Device Voltage Reference Input Circuit

Conditions for Running the DTC

This DTC will run only if the DIM has power and ground. This DTC will execute regardless of the source voltage.

Conditions for Setting the DTC

This code shall be set after 10 consecutive readings that the 2 battery positive voltages differ by 1 volt or greater.

Action Taken When the DTC Sets

All writes to the EEPROM will be suspended. All loss of communication and low/high voltage DTC codes are suspended.

Conditions for Clearing the DTC
    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Step

Action

Values

Yes

No

Schematic Reference: Body Control System Schematics

Connector End View Reference: Computer/Integrating Systems Connector End Views

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. Turn OFF the ignition.
  2. Disconnect the dash integration module (DIM).
  3. Turn ON the ignition, with the engine OFF.
  4. Measure and record the voltage from both battery positive voltage circuits of the DIM to both ground circuits of the DIM.
  5. Compare the two recorded DIM battery positive voltage circuit voltages.

Is the voltage difference less than the specified value?

1 V

Go to Step 5

Go to Step 3

3

Test both DIM battery positive voltage circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 4

4

Test both DIM ground circuits for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 5

5

Inspect for poor connections and terminal tension at the harness connector of the DIM. 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 7

Go to Step 6

6

Replace the DIM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 7

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7
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK