For 1990-2009 cars
ABS Components
Cell 44: Buick Indicators
Cell 44: Pontiac Indicators
Cell 44: Oldsmobile Indicators
Cell 10: IGN SW Fuse (1 of 2)
Cell 10: PCM Fuse
Cell 14: G202
Cell 14: G105 (2 of 4)
Cell 14: G102 and G105 (1 of 4)
Cell 14: G105 (3 of 4)
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice
Cell 50: UART Serial Data Line

### Circuit Description

If the vehicle is equipped with a U23, or a UH8 IPC, then the TRACTION OFF indicator is controlled by the serial data transmitted over the UART line from the EBTCM to the IPC.

If the vehicle is equipped with and IPC other then those stated above, then the TRACTION OFF indicator driver circuit runs from the IPC through the brake lamp driver module to the EBTCM. The indicator is supplied voltage from the IPC. The EBTCM controls the TRACTION OFF indicator through the brake lamp driver module. The brake lamp driver module acts as an invertor, when the EBTCM supplies a ground for the brake lamp driver module, the indicator remains off. When the EBTCM removes the ground for the brake lamp driver module, the indicator turns on by using the ground at the brake lamp driver module terminal D. When the Traction Control switch is pressed, the EBTCM sees the voltage on CKT 1571 go low, the EBTCM disables Traction Control and removes the ground for the TRACTION OFF indicator and the indicator turns on.

### Diagnostic Aids

• | Buick uses two clusters: the U23 and the UB3. The U23 TRACTION OFF indicator is controlled by messages over the UART serial data line. The UB3 cluster is hard wired through the brake lamp driver moduleto the EBTCM. The EBTCM controls the TRACTION OFF indicator.

• | Oldsmobile uses one cluster: the UH8. The UH8 TRACTION OFF indicator is controlled by the UART serial data line.

• | Pontiac uses three different clusters: the UB3, the U50, and the U2F. All of these clusters are hard wired through the brake lamp driver module to the EBTCM. The EBTCM controls the TRACTION OFF indicator.

• | If the battery feed to the IPC indicators is open, then more than one indicator bulb will be inoperative.

### Test Description

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

1. This step checks if the IPC is controlled by serial data or hard wired through the LDM to the EBTCM.

2. This step checks if the IPC can turn the TRACTION OFF indicator on.

#### Traction Off Indicator Inoperative with No DTC Set

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 | Is this vehicle equipped with a U23, or a UH8 Instrument cluster? | -- | Go to Step 3 | Go to Step 7
3 |

1. Turn the ignition switch to the RUN position. Do not start the engine.
2. Use a scan tool in order to enter ABS Data List.
3. While monitoring the TCS ON/OFF Switch status, press and release the TCS switch.

Does the switch status change from pressed to released as the TCS switch is pressed and released?

--

Go to Step 4

Go to Step 24

4 | Use the scan tool in ABS/TCS Special Tests in order to command the TRACTION OFF indicator on. Does the indicator come on? | -- | Go to Step 5 | Go to Step 6
5 | Replace the EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
6 | Suspect IPC. Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Is the diagnosis complete? | -- | Go to Diagnostic System Check | --
7 |

1. Turn the ignition switch to the RUN position. Do not start the engine.
2. Use a scan tool in order to enter ABS Data List.
3. While monitoring the TCS ON/OFF Switch status, press and release he TCS switch.

Does the switch status change form pressed to released as the TCS switch is pressed and released?

--

Go to Step 8

Go to Step 24

8 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the EBTCM.
3. Turn the ignition switch to the RUN position. Do not start the engine.

Does the TRACTION OFF indicator turn on?

--

Go to Step 5

Go to Step 9

9 |

1. Turn the ignition switch to the OFF position.
2. Check the CHIME fuse D1 in the IP Fuse Block.

Is the fuse OK?

--

Go to Step 10

Go to Step 11

10 |

1. Install the fuse, if removed.
2. Turn the ignition switch to the RUN position. Do not start the engine.
3. Using J 39200 DMM, measure the voltage at the fuse test terminals.

Is the voltage within the specified range?

Battery Voltage

Go to Step 12

Go to Wiring Repairs in Wiring Systems

11 |

1. Turn the ignition switch to the OFF position.
2. Remove the CHIME fuse D1.
3. Disconnect the brake lamp driver module.
4. Using the J 39200 DMM, measure the resistance between terminal B of the brake lamp driver module connector harness side and a good ground.

Is the resistance equal to the specified value?

OL (infinite)

Go to Step 15

Go to Step 14

12 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the brake lamp driver module connector.
3. Turn the Ignition switch to the RUN position. Do not start the engine.
4. Using the J 39200 DMM, measure the voltage at terminal B of the brake lamp driver module harness connector to ground.

Is the voltage within the specified range?

Battery Voltage

Go to Step 13

Go to Step 23

13 | Check the voltage at terminal A of the brake lamp driver module harness connector. Is the voltage within the specified range? | Battery Voltage | Go to Step 16 | Go to Step 17
14 | Repair CKT 39 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
15 |

1. Replace the fuse.
2. Reconnect the brake lamp driver module.
3. Turn the ignition switch to the RUN position. Do not start the engine.
4. Recheck the CHIME fuse D1 in the IP Fuse Block.

Is the fuse OK?

--

Go to Diagnostic System Check

Go to Step 19

16 |

1. Turn the ignition switch to the OFF position.
2. Using the J 39200 DMM, measure the resistance between terminal D of the brake lamp driver module harness connector and a good ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 18

Go to Step 21

17 |

1. Turn the ignition switch to the OFF position.
2. Disconnect IPC connector C1.
3. Connect a fused jumper wire between CKT 1660 of the IPC harness connector and a good ground.
4. Using J 39200 DMM, measure the resistance between the brake lamp driver module harness connector terminal A and a good ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 6

Go to Step 22

18 |

1. Turn the ignition switch to the OFF position.
2. Install the J 39700 universal pinout box using the J 39700-25 cable adapter connected to the EBTCM harness connector only.
3. Using the J 39200 DMM, measure the resistance between terminals 7 and B of the J 39700 .

Is the resistance equal to the specified value?

OL (infinite)

Go to Step 19

Go to Step 20

19 | Replace the brake lamp driver module. Refer to Lamp Driver Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | --
20 | Repair CKT 1572 for a short to ground. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
21 | Repair CKT 1250 for an open. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
22 | Repair an open or high resistance in CKT 1660. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
23 | Repair an open or high resistance in CKT 39. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
24 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the EBTCM connector.
3. Connect J 39700 universal pinout box using the J 39700-25 cable adapter connected to the EBTCM harness connector only.
4. Have an assistance hold the traction control ON/OFF switch closed.
5. Using the J 39200 DMM, measure the resistance between terminal 2 of and B of the J 39700 .

Is the resistance less than the specified value?

5 ohms

Go to Step 5

Go to Step 25

25 |

1. Disconnect the traction control ON/OFF switch connector.
2. Connect a fused jumper wire between CKT 1571 of the traction control ON/OFF switch harness connector and a good ground.
3. Use the J 39200 DMM in order to measure the resistance between terminal 2 and terminal B of the J 39700

Is the resistance less than the specified value?

5 ohms

Go to Step 27

Go to Step 26

26 | Repair an open in CKT 1571. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
27 | Use the J 39200 DMM in order to measure the resistance between CKT 251 of the traction control ON/OFF switch harness connector and a good ground. Is the resistance less than the specified value? | -- | Go to Step 28 | Go to Step 29
28 | Replace the traction control switch. Refer to the appropriate procedure:

• | Electronic Traction Control Switch Replacement in Instrument Panel, Gauges and Console

• | Electronic Traction Control Switch Replacement in Instrument Panel, Gauges and Console

• | Electronic Traction Control Switch Replacement in Instrument Panel, Gauges and Console

Is the replacement complete?

--

Go to Diagnostic System Check

--

29 | Repair an open in CKT 251. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --