GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 DTC 🢒 DTC 9

Circuit Description

The body control module (BCM) sends serial data along the secondary serial data bus circuit. This is read by the instrument cluster to indicate the status of the various components on the serial data line. DTC 9 will set if there is no BCM data message on the bus for more than 10 seconds. In practice the trouble code is set somewhere between 10 and 20 seconds after the last BCM data message is received by the instrument cluster. The DTC is reset within 10 seconds of the arrival of a BCM data message on the bus. The DTC is logged as a History DTC.

Diagnostic Aids

By manipulating the harnesses at the various connectors it is often possible to isolate the cause of the circuit interruption. This harness can then be removed and repaired. Inspected for any damage to the harness which could cause an intermittent open circuit or backed out terminals at the instrument cluster connectors, broken connector locks, improperly formed or damaged terminals. The multimeter allows continuity of the wiring harness secondary serial data bus circuit to be checked. If the fault cannot be found in the harness then the fault may lie in the BCM. Refer to Diagnostic Starting Point - Body Control System in Body Control System for further diagnosis.

DTC 9 - NO SERIAL DATA FROM BCM

Step

Action

Yes

No

1

Did you perform the Instrument Cluster Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Instrument Cluster

2
  1. Install a scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. With the scan tool, observe the body control module (BCM) Data display.

Does the Tech 2 display BCM information?

Go to Step 3

Go to Scan Tool Does Not Communicate with UART Data Line in Data Link Communications

3
  1. Turn the ignition OFF.
  2. Remove the instrument cluster. Refer to Instrument Cluster Replacement .
  3. Gain access to the BCM. Refer to Body Control Module Replacement in Body Control System.
  4. Check continuity of the universal asynchronous receiver transmitter (UART) circuit between the BCM and the instrument panel (I/P). Refer to Circuit Testing in Wiring Systems.

Is continuity present?

Go to Step 4

Go to Step 6

4

Check the UART circuit between the BCM and the I/P for a short to ground. Refer to Circuit Testing in Wiring Systems.

Is a short present?

Go to Step 7

Go to Step 5

5

Check the UART circuit between the BCM and the I/P for a short to voltage. Refer to Circuit Testing in Wiring Systems.

Is a short present?

Go to Step 8

Go to Step 9

6

Repair the open or high resistance in the ground in the UART circuit between the electronic brake control module (EBCM) and the I/P. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

--

7

Repair the short to ground in the ground in the UART circuit between the EBCM and the I/P. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

--

8

Repair the short to voltage in the ground in the UART circuit between the EBCM and the I/P. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

--

9
  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