GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The keyboard data display (KDD) is the data bus used to communicate between the IPM and the climate control panel. The climate control panel is part the IPM and is serviced as one component. This is an internal error of the IPM.

Conditions for Setting the DTC

    • The ignition is ON.
    • Internal open or short.

Action Taken When the DTC Sets

A default value of 27°C (70°F) will be used by the IPM to allow operation of the system.

Conditions for Clearing the MIL/DTC

    • This DTC requires an ignition cycle to change from current to history.
    • The module no longer detects the internal error.
    • A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use a Scan Tool .
    • IPM battery voltage is interrupted.

Diagnostic Aids

DTC B1399 is an internal module malfunction, the module may need to be replaced. Refer to diagnostic table.

Test Description

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

  1. Perform the Body Control Module Diagnostic System Check before continuing with the diagnosis of this DTC.

  2. Clear all DTCs and cycle ignition to ensure the DTC was not set in error.

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

Step

Action

Value(s)

Yes

No

1

Was the Body Control Modules Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - Body Control System in Body Control Systems

2

  1. Turn ON the ignition switch.
  2. Using a Scan Tool clear any DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing in HVAC.
  3. Turn OFF the ignition switch.
  4. Turn ON the ignition switch.

Is the DTC still present?

--

Go to Step  3

System OK

3

Replace the IPM. Refer to Instrument Panel Module Replacement in HVAC.

Is the module replacement complete?

--

Go to Step  4

--

4

  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. Using a Scan Tool clear any DTCs.

Are all DTCs cleared?

--

Go to Diagnostic System Check - Body Control System in Body Control Systems

--