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

### Circuit Description

For vehicles equipped with a U23 or a UH8 instrument cluster, the TRACTION OFF indicator is controlled by the EBCM/EBTCM via serial data UART.

For vehicles equipped with a UB3, a U2F, or a U50 instrument cluster, the TRACTION OFF indicator is controlled by the EBCM/EBTCM via the brake lamp driver module. The instrument cluster or remote indicator bank supplies voltage to the indicator. The brake lamp driver module acts as an inverter. When the EBCM/EBTCM supplies ground to the brake lamp driver module, the indicator remains OFF. When the EBCM/EBTCM removes ground from the brake lamp driver module, the brake lamp driver module supplies ground to the TRACTION OFF indicator.

### Diagnostic Aids

• | Buick uses the U23 and the UB3 instrument clusters.

• | Oldsmobile uses the UH8 instrument cluster.

• | Pontiac uses the UB3, the U2F, and the U50 instrument clusters.

• | It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

• | An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.

• | If an intermittent malfunction exists, refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

### Test Description

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

1. This step inspects to see if the cluster is hard wired, or controlled by serial data.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - ABS
2 | Is this vehicle equipped with a U23 or a UH8 instrument cluster? | -- | Go to Step 3 | Go to Step 8
3 |

1. Turn ON the ignition leaving the engine OFF.
2. Use a scan tool in order to enter ABS/TCS data list.
3. While monitoring the TCS ON/OFF switch status, press and release the TCS switch.

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

--

Go to Step 6

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Install the J 39700 universal pinout box using the J 39700-25 cable adapter to the EBCM/EBTCM harness connector only.
3. Use the J 39200 DMM in order to measure the resistance between terminal 2 and terminal B of the J 39700 .

Does the resistance equal the specified value?

OL (infinite)

Go to Step 10

Go to Step 5

5 | Repair a short to ground in CKT 1571 (BRN/WHT). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check - ABS | --
6 |

1. Turn ON the ignition leaving the engine OFF.
2. Use a scan tool in ABS/TCS Special Functions in order to command the TRACTION OFF indicator off.

Does the indicator turn off?

--

Go to Step 10

Go to Step 7

7 | Inspect the instrument cluster. Refer to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console. Is the diagnosis complete? | -- | Go to Diagnostic System Check - ABS | --
8 |

1. Turn ON the ignition leaving the engine OFF.
2. Use a scan tool in order to enter the ABS/TCS data list.
3. While monitoring the TCS ON/OFF switch status, press and release the TCS switch.

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

--

Go to Step 9

Go to Step 4

9 |

1. Turn OFF the ignition.
2. Disconnect the EBCM/EBTCM connector.
3. Connect the J 39700 universal pinout box using the J 39700-25 cable adapter between the EBCM/EBTCM and the EBCM/EBTCM harness connector.
4. Connect a fused jumper between the EBCM/EBTCM connector terminal 7 and ground terminal B.
5. Turn ON the ignition leaving the engine OFF.

Does the TRACTION OFF indicator turn off?

--

Go to Step 10

Go to Step 11

10 | Replace the EBCM/EBTCM. Refer to Electronic Brake Control Module Replacement . Did you complete the repair? | -- | Go to Diagnostic System Check - ABS | --
11 |

1. Turn OFF the ignition.
2. Disconnect the brake lamp driver module.
3. Leave the fused jumper wire between terminal 7 and terminal B of the J 39700 .
4. Use the J 39200 DMM in order to measure the resistance between the brake lamp driver module harness connector terminal F and a good ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 12

Go to Step 15

12 | Turn ON the ignition leaving the engine OFF. Is the TRACTION OFF indicator on? | -- | Go to Step 13 | Go to Step 14
13 | Repair a short to ground in CKT 1660 (DK BLU). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check - ABS | --
14 | Replace the brake lamp driver module. Refer to Lamp Driver Module Replacement . Did you complete the repair? | -- | Go to Diagnostic System Check - ABS | --
15 | Repair an open in CKT 1572 (PPL/WHT). Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check - ABS | --