For 1990-2009 cars
ABS Components
Cell 44: Stoplamp/BTSI Switch, Inlet/Outlet Solenoid Valves, and Wheel Speed Sensors
Cell 10: TURN LPS, FLAT PACK MTR, PERIM LP, and ABS Fuses
Cell 10: ABS PUMP MOTOR, ABS MAIN, and COOLING FAN Fuses
Cell 14: G102, G104, G106, G110 and G301
Cell 14: G202 (1 of 3) (Buick)
Cell 14: G202 (1 of 3) (Oldsmobile)
Handling ESD Sensitive Parts Notice

### Circuit Description

The normally closed outlet valves operate similarly to the inlet valves. When the EBCM/EBTCM grounds an outlet valve, however, the valve opens instead of closes.

The EBCM/EBTCM opens an outlet valve for short periods in order to reduce pressure at the LR wheel.

### Conditions for Setting the DTC

The DTC C1256 sets when the EBCM/EBTCM detects an open or short to ground in the LR outlet valve circuit.

### Action Taken When the DTC Sets

The following actions are taken when the DTC sets:

• | A malfunction DTC is stored.

• | The ABS is disabled.

• | The ANTILOCK indicator lamp is turned ON.

### Conditions for Clearing the DTC

The DTC will clear under following conditions:

• | Conditions for the malfunction are no longer present. Use the scan tool Clear DTCs function.

• | 100 ignition switch key cycles have passed without detecting any malfunctions

### Diagnostic Aids

Perform a thorough inspection of the wiring and the connectors.

Failure to inspect wiring carefully may result in a misdiagnosis. A misdiagnosis may result in replacing parts without repairing the malfunction.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Diagnostic System Check performed? | -- | Go to Step 2 | Go to Diagnostic System Check
2 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the BPMV connector C1.
3. Use the J 39200 in order to measure the resistance between the BPMV connector C1 terminals 13 and 14.

Is the resistance less than the specified value?

2 ohms

Go to Step 3

Go to Step 13

3 | Measure the resistance between the BPMV connector C1 terminal 14 and the BPMV assembly block. Is the resistance equal to the specified value? | OL (Infinite) | Go to Step 4 | Go to Step 13
4 | Measure the resistance between the BPMV connector C1 terminals 14 and 10. Is the resistance within the specified range? | 3-6 ohms | Go to Step 5 | Go to Step 13
5 |

1. Disconnect the EBCM/EBTCM connector.
2. Install the J 38716 pinout box.
3. Measure the resistance between the J 38716 pinout box terminal 36 and the BPMV harness connector terminal 10.

Is the resistance less than the specified value?

2 ohms

Go to Step 6

Go to Step 9

6 |

1. Reconnect the BPMV harness connector C1.
2. Measure the resistance between the J 38716 pinout box terminal 1 and the ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 7

Go to Step 10

7 |

1. Disconnect the ABS main relay.
2. Measure the resistance between the J 38716 pinout box terminal 1 and the EBCM/EBTCM harness connector terminal 36.

Is the resistance equal to the specified value?

OL (Infinite)

Go to Step 8

Go to Step 11

8 |

1. Reinstall the ABS main relay.
2. Turn the ignition switch to the RUN position.
3. Use the J 39200 in order to measure the voltage between the J 38716 pinout box terminal 1 the EBCM/EBTCM harness connector terminal 36.

Is the voltage greater than the specified value?

1 V

Go to Step 12

Go to Step 14

9 | Repair the open or high resistance in CKT 1291. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
10 | Repair the open or high resistance in CKT 1451. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
11 | Repair the short to ground in CKT 1291. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
12 | Repair the short to voltage in CKT 1291. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Diagnostic System Check | --
13 | Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | --
14 | Replace the EBCM/EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the repair complete? | -- | Go to Diagnostic System Check | --