GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2003 🢒 Seville 🢒 Body and Accessories 🢒 Body Control System 🢒 DTC B1805
Table 1: Device Power Moding

Circuit Description

Normal vehicle class 2 communications will not commence until the system power mode has been identified. Four discrete wires from the ignition switch contacts are monitored by the dash integration module (DIM) in order to determine the present power mode. The DIM communicates the system power mode to all class 2 modules on the class 2 serial data line.

Conditions for Running the DTC

The DIM must be powered.

Conditions for Setting the DTC

One of the 4 monitored ignition switch circuits is open or shorted.

Action Taken When the DTC Sets

The DIM implements default actions for each ignition switch position when faults are detected.

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.

Device Power Moding

Key Position

Accessory (Ign. Accessory)

Crank (Ign Crank)

Ign 1 (Run/Crank)

Off/Run/Crank (Ign. Off/Run/Crank)

RUN

Active

Inactive

Active

Active

CRANK

Inactive

Active

Active

Active

ACCY

Active

Inactive

Inactive

Active

OFF

Inactive

Inactive

Inactive

Inactive

Test Description

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

  1. This step tests for a short to battery voltage on the active signal circuit.

    2.

  2. This step tests the inactive signal circuit for an open or a high resistance.

    3.

  3. If any ignition switch parameters that should be inactive in the present ignition switch position are active, 2 ignition switch signal circuits may be shorted together.

Step

Action

Yes

No

Schematic Reference: Body Control System Schematics

Connector End View Reference: Body Control System Connector End Views

1

Did you perform the Diagnostic System Check for the system exhibiting the symptom?

Go to Step 2

Go to Control Module References for the applicable Diagnostic System Check

2
  1. Install a scan tool.
  2. Turn OFF the ignition.
  3. With a scan tool, observe the ignition switch parameters in the dash integration module (DIM) input data list.

Do all of the ignition switch parameters display Inactive?

Go to Step 3

Go to Step 6

3
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the ignition switch parameters.

Do all of the ignition switch parameters display Active?

Go to Step 4

Go to Step 7

4
  1. Turn the ignition switch to the CRANK position.
  2. With a scan tool, observe the ignition switch parameters.

Do only the Run/Crank and Off/Run/Crank parameters display Active?

Go to Step 5

Go to Step 8

5
  1. Turn the ignition switch to the ACCY position.
  2. With a scan tool, observe the ignition switch parameters.

Does only the Ign. Accessory and Ign. Off/Run/Crank parameters display Active?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the ignition switch.
  3. With a scan tool, observe the ignition switch parameters.

Do all of the ignition switch parameters display Inactive?

Go to Step 12

Go to Step 9

7

  1. Turn OFF the ignition.
  2. Disconnect the dash integration module (DIM).
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the inactive signal circuit and a good ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 10

8

Do any other ignition switch parameters also indicate Active when the parameter should be Inactive?

Go to Step 11

Go to Step 12

9

Test the active signal circuit of the ignition switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 13

10

Test the inactive signal circuit of the ignition switch 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 16

Go to Step 12

11

Test the active signal circuit of the ignition switch for a short to another signal circuit of the ignition switch. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 12

12

Inspect for poor connections and terminal tension at the harness connector of the ignition switch. 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 16

Go to Step 14

13

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 16

Go to Step 15

14

Replace the ignition switch. Refer to Ignition and Start Switch Replacement in Instrument Panel Gages and Console

Did you complete the replacement?

Go to Step 16

--

15

Important:: After replacement of the DIM perform the set up procedure for the DIM. Refer to Body Control Module (BCM) Programming/RPO Configuration .

Replace the DIM. Refer to Dash Integration Module Replacement .

Did you complete the replacement?

Go to Step 16

--

16
  1. Use a 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