GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Integrated Radio Controller (IRC) and the CD changer communicate on the E&C data line. The IRC sets DTC B1760 when it detects a loss of E&C communications with the CD Changer. If the CD changer is not heard from, the IRC initiates communications with the CD changer to determine its integrity.

Conditions for Setting the DTC

    • This algorithm shall execute when the radio transitions from the OFF to the ON mode.
    • DTC B1760 will set if the IRC detects a loss of E&C communication between the radio and the CD changer.

Action Taken When the DTC Sets

    • DTC B1760 is stored in the IRC memory.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

DTC B1760 will clear when the ignition switch is cycled.

Diagnostic Aids

If this DTC is intermittent, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step checks circuit B220 for continuity.

  2. This step replaces the CD changer.

Step

Action

Value(s)

Yes

No

1

Was the Radio/Audio System Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

  1. Disconnect the radio connector.
  2. Disconnect the CD Changer connector.
  3. Use the DMM to measure the resistance between terminal E1 of the radio connector and terminal 7 of the CD changer connector.

Is the measured resistance less than the specified value?

.5 ohms

Go to Step 4

Go to Step 3

3

Locate and repair an open in CKT B220 (YEL).

Is the repair complete?

--

Go to Step 5

--

4

Replace the CD changer.

Is the replacement complete?

--

Go to Step 5

--

5

  1. Connect all connectors and components that were disconnected.
  2. Verify that the radio and the CD changer operate properly.

Does the radio and the CD changer operate properly?

--

System OK

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