GM Service Manual Online
For 1990-2009 cars only

Circuit Description

An auxiliary video input jack closes the auxiliary detection signal circuit. If the auxiliary detection signal circuit opens, the radio sets this DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2475 Navigation Display Head (NDH) Auxiliary Input Performance

Conditions for Running the DTC

    • The navigation radio must detect one of the following power modes:
       - ACC
       - ON
       - RAP
       - RAP UNLCK
    • The navigation system must be equipped with the TV option (RPO UE7).
    • The radio does not set this DTC if B1328 or B1327 is current.

Conditions for Setting the DTC

The radio tests the auxiliary detection signal circuit every second.

Action Taken When the DTC Sets

    • Cannot play auxiliary inputs in to the TV.
    • The AUX SWITCH is not displayed on the screen.

Conditions for Clearing the DTC

A current DTC clears and becomes a history DTC if the navigation radio does not detect the failure for more than one second.

Diagnostic Aids

An intermittent condition may be caused by the following:

    • Mis-routed harness
    • Rubbed through wire insulation
    • Broken wire inside the insulation
    • Poor connections in the harness connectors.

Test Description

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

  1. Determines if the malfunction is present.

  2. Tests the auxiliary detection signal for the correct voltage range.

Step

Action

Value(s)

Yes

No

Schematic Reference: Navigation System Schematics

1

Did you perform Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn the ignition OFF.
  2. Disconnect the auxiliary input jack harness connector.
  3. Turn the ignition ON with the engine OFF.
  4. Measure the voltage between the auxiliary detection signal circuit and ground.

Is the value within the range specified?

4.5-5.5 V

Go to Step 6

Go to Step 3

3

  1. Turn the ignition switch OFF.
  2. Disconnect the navigation radio connector.
  3. Test the auxiliary detection signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 8

Go to Step 4

4

Inspect for poor connections at the harness connector of the navigation radio. 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 8

Go to Step 5

5

Replace the navigation radio. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 8

--

6

Inspect for poor connections at the harness connector of the auxiliary RCA video jacks. 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 8

Go to Step 7

7

Replace the auxiliary RCA video jacks. Refer to Audio/Video Wiring Harness Replacement .

Did you complete the replacement?

--

Go to Step 8

--

8

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

Does the DTC reset?

--

Go to Step 2

System OK