GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Bonneville 🢒 Body and Accessories 🢒 Data Link Communications 🢒 DTC U1161-U1163 or U1170

Circuit Description

The power door serial data circuit provides a means for communication between the vehicle door modules. Door module information on inputs and commanded outputs are converted to power door serial data for exchange among the door modules. This includes the driver door switch assembly (DDSA), which is also a door module. The driver door module (DDM) can also take information from modules connected to the class 2 serial data circuit and relay the command to the power door serial data link. The vehicle power mode message (ignition switch position) from the DIM is an example. The DDM periodically addresses each door module on the power door serial data circuit. When a door module does not respond to the DDM, the DTC for that module is set.

Conditions for Running the DTC
    • Diagnostic trouble codes B1327, B1328, U1300, and U1301 do not have a current status.
    • The driver door module has power.
    • The driver door module has received an input, a power door serial data message or a class 2 wake-up message.

Conditions for Setting the DTC

When a door module or the DDSA does not respond to the DDM within 2 seconds of the DDM request for a response, the DDM sets the appropriate DTC.

Conditions for Clearing the DTC
    • A current DTC will clear when a response message from the failed door module is detected or at the end of the current ignition cycle.
    • A history DTC will clear upon receipt of a scan tool Clear DTCs command or after 50 OFF/ON ignition switch cycles without a repeat of a communications failure.

Test Description

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

  1. This step determines if there is a total malfunction of the power door serial data circuit, a condition which would set diagnostic trouble codes U1161, U1162, U1163, and U1170 simultaneously.

    2.

  2. When DTCs U1161, U1162, and U1163 set simultaneously but U1170 does not set, the malfunction is likely to be caused by an open in the power door serial data circuit between the DDM and splice S302

    3.

  3. Loss of communications with individual door modules may be due to an unpowered door module, a condition which would set, either DTC U1161, U1162, U1163, or U1170 individually.

    The driver door module (DDM) is powered by the DRVMDL 10 amp fuse and the front passenger door (PDM) is powered by the PASS MDL 10 amp fuse. The DDM, in addition, supplies power from the DRVMDL fuse to the driver door switch assembly (DDSA) via a separate battery positive voltage circuit.

    The rear door modules each have a separate battery positive voltage circuit, however, both circuits are powered by the RRDRMDL 10 amp fuse. If either one of the rear door modules battery positive voltage circuits is shorted to ground, the RRDRMDL fuse will open and cause DTCs U1162 and U1163 to be set simultaneously current.

  4. Loss of communications with individual door modules may be due to an ungrounded door module. This step determines if the door module that is not communicating has lost ground.

    The ground circuit for the driver door switch assembly (DDSA) is supplied by the driver door module.

    5.

  5. This step begins to determine where the power door serial data circuit short to voltage or ground is located. The shorted condition may be due to the wiring or due to a malfunction in one of the modules. When testing the wiring for a short, make sure there is not a module connected to the wire being tested.

    6.

  6. By operating the window and locks from the scan tool via the class 2 serial data circuit, this step proves that the DDM is capable of controlling the driver door functions and isolates the cause of the malfunction to the power door serial data circuit.

    7.

  7. By operating the driver door window and lock from the driver door switch assembly (DDSA), this step determines if the DDSA is the cause of the malfunction.

    8.

  8. This step, and the following steps, isolate the door module which is preventing power door serial data communications.

Step

Action

Yes

No

Schematic Reference: Door Control Module Schematics

Important:: Where it is not otherwise specified in the step, the following diagnostic procedure should be conducted with the ignition turned OFF to prevent an erroneous setting of DTC B0490.

1

Did you record DTCs U1161, U1162, U1163, and U1170 all with a current status?

Go to Step 8

Go to Step 2

2

Did you record DTCs U1161, U1162, and U1163 all with a current status but not U1170?

Go to Step 4

Go to Step 3

3

Did you record DTC U1161, DTC U1162, DTC U1163 or DTC U1170 by itself, or, DTCs U1162 and U1163 together with a current status?

Go to Step 5

Go to Testing for Electrical Intermittents in Wiring Systems

4

Test the power door serial data circuit for an open between the DDM and the circuit splice.

Did you find and correct the condition?

Go to Step 21

Go to Step 15

5

Important:: If the DTC set by itself is U1170, test the battery positive voltage circuit between the driver door module (DDM) and the driver door switch assembly (DDSA) for an open or a short to ground.

If DTCs U1162 and U1163 are simultaneously set, test the battery positive voltage circuit of both rear door modules for an open or a short to ground.

Test the battery positive voltage circuit associated with connector C1 of the module that is not communicating for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 6

6

Important: If the DTC set by itself is U1170, test the ground circuit between the driver door module (DDM) and the driver door switch assembly (DDSA) for an open.

  1. Turn OFF the ignition.
  2. Test the ground circuit, associated with connector C1, of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 7

7

Test the power door serial data circuit of the module that is not communicating for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 16

8

  1. Turn OFF the ignition.
  2. Disconnect the DDM from the DDSA.
  3. Test the power door serial data circuit between the DDM and DDSA for a short to ground or a short to voltage.
  4. Turn ON the ignition, with the engine OFF when you test for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 9

9
  1. Turn OFF the ignition.
  2. Disconnect the PDM, the LRDM and the RRDM.
  3. Test the power door serial data circuit of each module for a short to ground or a short to voltage.
  4. Turn ON the ignition, with the engine OFF when you test for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 10

10
  1. Connect the DDM.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Select the Special Functions for the DDM.
  5. With the scan tool, operate the driver door power window.
  6. With the scan tool, operate the driver door power lock.

Does the window or lock operate properly?

Go to Step 11

Go to Step 15

11
  1. Turn OFF the ignition.
  2. Connect the DDSA.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the driver door power window from the driver door switch assembly (DDSA).
  5. Operate the driver door power lock from the driver door switch.

Does the window or lock operate properly?

Go to Step 12

Go to Step 17

12

Important: Operate the power window from the switch at the passenger door before operating it from the driver door switch assembly (DDSA). The following procedure assumes the power window operates properly.

  1. Turn OFF the ignition.
  2. Connect the PDM.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the passenger door power window from the driver door switch assembly (DDSA).

Does the window operate properly?

Go to Step 13

Go to Step 16

13

Important: Operate the power window from the switch at the left rear door before operating it from the driver door switch assembly (DDSA). The following procedure assumes the power window operates properly.

  1. Turn OFF the ignition.
  2. Connect the LRDM.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the left rear door power window from the driver door switch assembly (DDSA).

Does the window operate properly?

Go to Step 14

Go to Step 16

14

Important: Operate the power window from the switch at the right rear door before operating it from the driver door switch assembly (DDSA). The following procedure assumes the power window operates properly.

  1. Turn OFF the ignition.
  2. Connect the RRDM.
  3. Turn ON the ignition, with the engine OFF.
  4. Operate the right rear door power window from the driver door switch assembly (DDSA).

Does the window operate properly?

Go to Step 15

Go to Step 16

15

Inspect for poor connections at the harness connector of the DDM. 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 21

Go to Step 18

16

Inspect for poor connections at the harness connector of the module that is not communicating. 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 21

Go to Step 19

17

Inspect for poor connections at the harness connector o the DDSA. 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 21

Go to Step 20

18

Replace the DDM. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 21

--

19

Replace the inoperative door module. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 21

--

20

Replace the DDSA. Refer to Front Door Switch Replacement .

Did you complete the replacement?

Go to Step 21

--

21
  1. Use the scan tool in order to clear the DDM 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