GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The PCM uses the serial data circuit to communicate with various other devices and systems in the vehicle. The PCM ensures that communication remains established by monitoring the serial data circuit for state of health messages from the other devices using the circuit. If the PCM detects a loss of the state of health serial data message from the Standard Body Module, DTC P1610 will be set.

Conditions for Running the DTC

    • The ignition is on.
    • System voltage is greater than 8.2 volts.

Conditions for Setting the DTC

The PCM is detecting a loss of serial data communications with the Body Control Module for longer than 5 seconds.

Action Taken When the DTC Sets

    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

    • A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear Info function.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed through wire insulation or a wire broken inside the insulation. Check for the following conditions:

    •  Intermittent short circuit on the serial data circuit.
         Refer to Data Link Connector (DLC) System check in Electrical Diagnosis and check all related wiring for an intermittent short to ground or short to voltage.
    •  Poor connection.
         Inspect the PCM and the affected control module harness and related connectors for improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
    •  Damaged harness.
         Inspect the wiring harness for damage. Check for an intermittent short or open circuit in the wiring harnesses related to the affected control module, including the ignition positive voltage, battery positive voltage, ground, and serial data circuits. Refer to Troubleshooting Procedures in Electrical Diagnosis.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the conditions.

Attempting to start the vehicle by bypassing the Theft Deterrent system or substituting parts without performing the password learn procedure may set a DTC P1631.

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If a loss of DLC data has already been diagnosed using the DLC Diagnosis table, clear this DTC and continue diagnosis with Powertrain On Board Diagnostic (OBD) System Check .

Attempt to select Body Control Module data with the scan tool.

Can Body Control Module data be displayed?

--

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition switch.
  2. Disconnect the PCM and the Body Control Module.
  3. Check the serial data circuit for an open between the Body Control Module and the PCM. Refer to Data Link Connector in Electrical Diagnosis.
  4. If a problem is found, repair as necessary. Refer to Wiring Repairs .

Was a problem found?

--

Go to Step 6

Go to Diagnostic Aids

4

  1. Check the serial data circuit for a poor connection at the Body Control Module.
  2. If a problem is found, repair as necessary. Refer to Testing for Continuity , Intermittents and Poor Connections Diagnosis , Repairing Connector Terminals and Connector Repairs .

Was a problem found?

--

Go to Step 6

Go to Step 5

5

  1. Check the serial data circuit for a poor connection at the PCM.
  2. If a problem is found, repair as necessary. Refer to Testing for Continuity , Intermittents and Poor Connections Diagnosis , Repairing Connector Terminals and Connector Repairs .

Was a problem found?

--

Go to Step 6

Go to Diagnostic System Check - Body Control System

6

  1. Review and record scan tool Fail Records data.
  2. Clear DTCs.
  3. Operate the vehicle within Fail Records conditions.
  4. Using a scan tool, monitor Specific DTC info for DTC P1610.

Does the scan tool indicate DTC P1610 failed?

--

Go to Step 2

System OK