GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Riviera 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1215 Suspect Valve Malfunction

Circuit Description

When the ignition is first turned to RUN, the EBCM/EBTCM goes through a self-check which lasts 2-4 seconds.

During this test, the EBCM/EBTCM grounds terminal 34. This energizes the main relay. Once the self-check is completed, the main relay remains energized. This delivers battery voltage to both the EBCM/EBTCM and the BPMV during vehicle operation. The constant voltage supply allows the vehicle to enter ABS mode without delay.

The main relay is de-energized whenever a system malfunction causes the amber ANTILOCK indicator to illuminate. This causes the ABS system to shut down.

Conditions for Setting the DTC

DTC C1215 sets under the following conditions:

    • The ignition switch is in RUN.
    • The EBCM/EBTCM detects a failure with one of the valves, but cannot determine which valve is faulted.

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 is turned ON.

Conditions for Clearing the DTC

The DTC will be cleared 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 with no malfunctions detected.

Diagnostic Aids

The following conditions may cause a suspect valve malfunction:

    • An open in any inlet or outlet valve circuit
    • A short to ground in any inlet or outlet valve circuit
    • High resistance in any inlet or outlet valve circuit control
    • If the vehicle is equipped with traction control, high resistance in either isolation valve circuit

Test Description

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

  1. This step checks for an open power feed for the solenoids internal to the BPMV.

    2.

  2. This step ensures that the BPMV is not internally shorted to the ground.

    3.

  3. This step checks the resistance of all of the solenoids.

    4.

  4. This step rechecks the resistance of the solenoids through the wiring harness between the EBCM/EBTCM and the BPMV.

    5.

  5. This step checks the integrity of CKT 1633 to the EBCM/EBTCM and the BPMV.

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. Test the connector for proper terminal contact.
  4. Use the J 39200 digital multimeter (DMM) in order to measure the resistance between terminal 13 and terminal 14.

Is the resistance less than the specified value?

2 ohms

Go to Step 3

Go to Step 22

3

Measure the resistance between the connector C1 terminal 14 and the BPMV valve block.

Is the resistance within the specified range?

OL (Infinite)

Go to Step 4

Go to Step 22

4

  1. Measure the resistance between the connector C1 terminal 14 and all of the inlet valve terminals (3, 5, 7 and 9).
  2. Measure the resistance between the connector C1 terminal 14 and all of the outlet valve terminals (4, 6, 8 and 10).
  3. Measure the resistance between the connector C1 terminal 14 and all of the isolation valve terminals, if equipped with TCS (1 and 2).

Is the resistance within the specified range?

Inlet and Isolation valves:

5-8 ohms

Outlet valves:

3-6 ohms

Go to Step 5

Go to Step 22

5

  1. Reconnect the connector C1.
  2. Disconnect the EBCM/EBTCM connector.
  3. Install the J 38716 pinout box.
  4. Measure the resistance between the J 38716 terminal 3 and all of the inlet valve terminals (20, 38, 54 and 55).
  5. Measure the resistance between the J 38716 terminal 3 and all of the outlet valve terminals (2, 18, 21 and 36).
  6. Measure the resistance between the J 38716 terminal 3 and all isolation valve terminals, if equipped with TCS (37 and 40).

Is the resistance within the specified range?

Inlet and Isolation valves:

5-8 ohms

Outlet valves:

3-6ohms

Go to Step 6

Go to Step 23

6

Measure the resistance between the J 38716 terminal 1 and a good ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 7

Go to Step 24

7
  1. Disconnect the ABS main relay.
  2. Measure the resistance between the J 38716 terminal 1 and all of the valve terminals (2, 18, 20, 21, 36, 38, 40, 54, and 55).

Is the resistance within the specified range?

OL (Infinite)

Go to Step 8

Go to Step 25

8
  1. Reinstall the ABS main relay.
  2. Turn the ignition switch to the RUN position.
  3. Use the J 39200 DMM in order to measure the voltage between the pinout box terminal 1 and all of the valve terminals (2, 18, 20, 21, 36, 37, 38, 40, 54 and 55).

Is the voltage less than the specified value?

1 V

Go to Step 9

Go to Step 26

9
  1. Connect a fused jumper wire with a 3A fuse between the J 38716 terminal 1 and terminal 34.
  2. Turn the ignition switch to the RUN position.

Does the ANTILOCK indicator turn OFF?

--

Go to Step 10

Go to Step 11

10

  1. Use the J 39200 DMM in order to measure the voltage between the pinout box terminal 1 and terminal 3.
  2. Use the J 39200 DMM in order to measure the voltage between pinout box terminal 1 and terminal 33.
  3. Use the J 39200 DMM in order to measure the voltage between the BPMV harness side connector C1 terminal 13 and the ground.
  4. Use the J 39200 DMM in order to measure the voltage between the BPMV harness side connector C1 terminal 14 and the ground.

Is the voltage within the specified range?

Battery Voltage

Go to Step 35

Go to Step 27

11
  1. Turn the ignition switch to the OFF position.
  2. Remove the fused jumper.
  3. Disconnect the ABS main relay.
  4. Measure the resistance between the ABS main relay terminal 30 and terminal 87A.

Is the resistance less than the specified value?

2 ohms

Go to Step 12

Go to Step 28

12

Measure the resistance between ABS main relay terminal 85 and terminal 86.

Is the resistance within the specified range?

40-90 ohms

Go to Step 13

Go to Step 28

13

Measure the resistance between the ABS main relay harness connector 87A and the ground.

Is the resistance less than the specified value?

2 ohms

Go to Step 14

Go to Step 29

14
  1. Turn the ignition switch to the OFF position.
  2. Measure the voltage at the ABS main relay harness connector terminal 87.

Is the voltage within the specified range?

Battery Voltage

Go to Step 15

Go to Step 20

15
  1. Turn the ignition switch to the RUN position.
  2. Measure the voltage between the ABS main relay harness connector terminal 86 and the ground.

Is the voltage within the specified range?

Battery Voltage

Go to Step 16

Go to Step 17

16
  1. Turn the ignition switch to the OFF position.
  2. Install a fused jumper between the ABS main relay harness connector terminal 30 and terminal 87.
  3. Measure the voltage between the J 38716 pinout box terminal 33 and terminal 1.
  4. Measure the voltage between the J 38716 pinout box terminal 3 and terminal 1.
  5. Measure the voltage between the BPMV harness connector terminal 14 and the ground.
  6. Measure the voltage between the BPMV harness connector terminal 13 and the ground.

Is the voltage within the specified range?

Battery Voltage

Go to Step 18

Go to Step 27

17

Remove and inspect the IP fuse block ABS fuse.

Is the fuse open?

--

Go to Step 32

Go to Step 33

18
  1. Turn the ignition switch to the OFF position.
  2. Move the fused jumper to the ABS main relay harness connector terminal 85 and terminal 86.
  3. Turn the ignition switch to the RUN position.
  4. Measure the voltage between the J 38716 pinout box terminal 34 and terminal 1.

Is the voltage within the specified range?

Battery Voltage

Go to Step 28

Go to Step 19

19

Remove and inspect the IP fuse block ABS fuse.

Is the fuse open?

--

Go to Step 21

Go to Step 34

20

Remove and inspect the engine compartment fuse block ABS MAIN fuse.

Is the fuse open?

--

Go to Step 30

Go to Step 31

21

Repair the short to ground in CKT 1632.

Is the repair complete?

--

Go to Diagnostic System Check

--

22

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

Is the repair complete?

--

Go to Diagnostic System Check

--

23

Repair the open or high resistance in the suspect circuit between the BPMV and the EBCM/EBTCM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

24

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

--

25

Repair the short to ground in the suspect circuit between the EBCM/EBTCM and the BPMV. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

26

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

Is the repair complete?

--

Go to Diagnostic System Check

--

27

Repair the open or high resistance in CKT 1633. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

28

Replace the ABS main relay. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

29

Repair the open in CKT 351. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

30

Repair the short to ground in CKT 1633 or CKT 242. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

31

Repair the open or high resistance in CKT 242. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

32

Repair the short to the ground in CKT 441. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

33

Repair the open or high resistance in CKT 441. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

34

Repair the open or high resistance in CKT 1632. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

35

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

Is the repair complete?

--

Go to Diagnostic System Check

--