GM Service Manual Online
For 1990-2009 cars only

Object Number: 406529  Size: LF
ABS Components
Cell 44: Stoplamp/BTSI Switch, Inlet/Outlet Solenoid Valve, and WHEEl Speed Sensors
Handling ESD Sensitive Parts Notice
Cell 10: TURNLPS Fuse, FLAT PACK MTR Fuse, PERIM LP Fuse, and ABS Fuse
Cell 10: ABS PUMP MOTOR Fuse, ABS MAIN Fuse, and COOLING FAN Fuse
Cell 14: G202 (Buick 1 of 3)
Cell 14: G202 (Oldsmobile 2 of 3)
Cell 44: PWR, GND, and ABS Relays
Cell 14: G102, G104, G106, G110, and G301 (Battery Ground)

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 RR wheel.

Conditions for Setting the DTC

The DTC C1252 sets when the EBCM/EBTCM detects an open or short to ground in the RR 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 ABS Diagnostic System Check performed?

--

Go to Step  2

Go to Diagnostic System Check - ABS

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 terminal 13 and terminal 14.

Is the resistance less than the specified value?

2 ohms

Go to Step  3

Go to Step  13

3

Use the J 39200 in order to measure the resistance between the BPMV connector C1 terminal 14 and the BPMV assembly block.

Is the resistance within the specified range?

OL (Infinite)

Go to Step  4

Go to Step  13

4

Use the J 39200 in order to measure the resistance between the BPMV connector C1 terminal 14 and terminal 8.

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. Use the J 39200 in order to measure the resistance between the J 38716 pinout box terminal 18 and the BPMV harness connector terminal 8.

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. Use the J 39200 in order to measure the resistance between the J 38716 pinout box terminal 1 and the vehicle 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. Use the J 39200 in order to measure the resistance between the J 38716 pinout box terminal 1 and the EBCM/EBTCM harness connector terminal 18.

Is the resistance within the specified range?

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 terminal 1 and the EBCM/EBTCM harness connector terminal 18.

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 863. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

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 - ABS

--

11

Repair the short to ground in CKT 863. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

12

Repair the short to voltage in CKT 863. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

13

Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

14

Replace the EBCM/EBTCM. Refer to Electronic Brake and Traction Control Module Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--