GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Park Avenue 🢒 DTC 🢒 DTC C1235 RR Wheel Speed Circuit Open or Shorted

Object Number: 397525 Size: MF
ABS Components
Cell 44: Wheel Speed Sensors and Variable Steering Actuator
Handling ESD Sensitive Parts Notice

Circuit Description

The wheel speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal. The EBCM/EBTCM uses the frequency of the AC signal to calculate the wheel speed.

Conditions for Setting the DTC

All of the following conditions occur:

    • The ignition is ON.
    • The EBCM/EBTCM detects one of the following conditions:
       - An open
       - A short to ground
       - A short to voltage

Action Taken When the DTC Sets
    • A DTC C1235 is stored
    • The ABS/TCS is disabled
    • The ABS and the TRACTION OFF indicators are turned on

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present and you used the scan tool Clear DTC function.
    • The EBCM/EBTCM does not detect the DTC in 50 drive cycles.

Diagnostic Aids
    • Thoroughly inspect the wiring and the connectors. Failure to carefully and fully inspect the wiring and the connectors can result in misdiagnosis. Misdiagnosis may cause replacement of parts without repairing the malfunction.
    • The following conditions may cause an intermittent malfunction:
       - Poor connections
       - Broken insulation
       - A broken wire inside the insulation
    • If an intermittent malfunction exists, refer to Testing for Electrical Intermittents in Wiring Systems.

Test Description

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

  1. Checks for an open in the WSS or WSS CKT.

    2.

  2. Checks for a short to ground in the WSS or WSS CKT.

    3.

  3. Checks for a short to voltage in the WSS CKT.

    4.

  4. Checks for a short to voltage in the WSS CKT.

DTC C1235 RR Wheel Speed Sensor Circuit Open or Shorted

Step

Action

Value(s)

Yes

No

1

Was the ABS Diagnostic System Check performed?

--

Go to Step  2

Go to Diagnostic System Check

2
  1. Inspect the WSS wiring and connectors for damage.
  2. Inspect the WSS for looseness or damage.

Is physical damage of sensor evident?

--

Go to Step  3

Go to Step  4

3

Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

4

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the EBCM/EBTCM.
  3. Install the J 39700 universal pinout box using the J 39700-25 cable adapter to the EBCM/EBTCM harness connector only.
  4. Using the J 39200 DMM, measure the resistance between terminals  13 and 29 of the J 39700 .

Is the resistance within the specified range?

850 - 1350 ohms

Go to Step  12

Go to Step  5

5
  1. Disconnect the RR wheel speed sensor.
  2. Using the J 39200 DMM, measure the resistance between terminals A and B of the wheel speed sensor connector.

Is the resistance within the specified range?

850 - 1350 ohms

Go to Step  6

Go to Step  11

6
  1. Connect a jumper between the RR wheel speed sensor harness connector terminal B and ground.
  2. Using the J 39200 DMM, measure the resistance between terminals 29 and B of theJ 39700 .

Is the resistance less than the specified value?

0 - 5 ohms

Go to Step  8

Go to Step  7

7

Repair CKT 882 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

8
  1. Connect a jumper between the RR wheel speed sensor harness connector terminal A and ground.
  2. Using the J 39200 DMM, measure the resistance between terminals 13 and B of the J 39700 .

Is the resistance less than the specified value?

0 - 5 ohms

Go to Step  10

Go to Step  9

9

Repair CKT 883 for an open or high resistance. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

10

Malfunction is intermittent. Inspect all connectors and harnesses for damage that may result in an open or high resistance when connected. Refer to Testing for Electrical Intermittents in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

11

Replace the wheel speed sensor. Refer to Rear Wheel Bearing and Hub Replacement in Rear Suspension.

Is the replacement complete?

--

Go to Diagnostic System Check

--

12

Using the J 39200 DMM, measure the resistance between terminals 13 and B of the J 39700 .

Is the resistance within the specified range?

OL (infinite)

Go to Step  19

Go to Step  13

13
  1. Disconnect the RR wheel speed sensor.
  2. Using J 39200 DMM, measure the resistance between terminal A and ground of the wheel speed sensor connector.

Is the resistance within the specified range?

OL (infinite)

Go to Step  14

Go to Step  11

14

Using the J 39200 DMM, measure the resistance between terminals 29 and B of the J 39700 .

Is the resistance within the specified range?

OL (infinite)

Go to Step  16

Go to Step  15

15

Repair CKT 882 for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

16

Using the J 39200 DMM, measure the resistance between terminals 13 and B of the J 39700 .

Is the resistance within the specified range?

OL (infinite)

Go to Step  17

Go to Step  18

17

Malfunction is intermittent. Inspect all connectors and harnesses for damage that may result in a short to ground when connected. Refer to Intermittents and Poor Connections in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

18

Repair CKT 883 for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

19

  1. Disconnect the RR wheel speed sensor.
  2. Turn the ignition switch to the RUN position, engine off.
  3. Using the J 39200 DMM, measure the voltage from terminal 29 to terminal B of the J 39700 .

Is the voltage greater than the specified value?

1 V

Go to Step  20

Go to Step  21

20

Repair CKT 882 for a short to voltage. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

21

Using the J 39200 DMM, measure the voltage from terminal  13 to terminal  B of the J 39700 .

Is the voltage greater than the specified value?

1 V

Go to Step  22

Go to Step  23

22

Repair CKT 883 for a short to voltage. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check

--

23

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

Is the replacement complete?

--

Go to Diagnostic System Check

--