GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Optra - Mexico 🢒 Restraints 🢒 SIR 🢒 DTC C0245

Circuit Description

The toothed wheel generates a voltage pulse as it moves past the wheel speed sensor (WSS). Each tooth-gap-tooth series on the wheel generates the pulses. The electronic brake control module (EBCM) uses the frequency of these pulses to determine wheel speed. The voltage generated depends on the air gap between the wheel speed sensor and the toothed wheel, and on the wheel speed.

This DTC will set when the EBCM cannot identify which wheel speed sensor is causing the malfunction. It is necessary to inspect all wheel speed sensors and associated wiring to determine the cause of the DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC C0245 Wheel Speed Signal Malfunction

Conditions for Running the DTC
    • Vehicle speed is greater than 6 km/h (4 mph) with the brake pedal not applied
        or
    • Vehicle speed is greater than 15 km/h (9 mph) and the brake pedal is actuated.

Conditions for Setting the DTC
    •  Incorrect number of teeth on the toothed wheel
    • Damaged or broken teeth on the toothed wheel
    • Discontinuity or short in the wheel speed sensor wiring

Action Taken When the DTC Sets

Antilock brake system (ABS) action is disabled and the ABS warning lamp is ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

DTC C0245 may be set by running the scan tool auto test if the throttle angle readings are not updating while in the data list mode. If this is the case, clear the DTCs, disconnect the scan tool, and road test the vehicle to at least 12 km/h (7 mph) to see if the DTC resets.

Inspect the toothed wheels for any large grooves, gouges, marks, etc. that might influence the tooth's signal at the wheel speed sensor. Also inspect for a buildup of foreign material in the gaps between the teeth in the toothed wheel. A buildup of foreign material may cause this malfunction.

A badly worn hub/bearing assembly may cause this malfunction. The wheel speed sensor-to-toothed wheel air gap may change excessively due to bearing play. If an improper rear hub assembly or front outer constant velocity joint is installed, one with a toothed wheel containing the incorrect number of teeth, this DTC can set. Be sure that the front and the rear toothed wheel have 47 and 29 teeth.

Test Description

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

  1. This step begins the examination of the front wheel speed sensors.

    2.

  2. This step inspects for a problem with one of the front toothed rings.

    3.

  3. This step inspects the front wheel speed sensors.

    4.

  4. This step inspects for shorts in a front wheel speed sensor harness.

    5.

  5. This step inspects for opens in a front wheel speed sensor harness.

    6.

  6. This step begins an inspection of the rear wheel speed sensors.

    7.

  7. This step inspects for a problem with one of the rear toothed rings.

    8.

  8. This step inspects the rear wheel speed sensors.

    9.

  9. This step inspects for shorts in a rear wheel speed sensor harness.

    10.

  10. This step inspects for opens in a rear wheel speed sensor harness.

Step

Action

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

Connector End View Reference: Antilock Brake System Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Visually inspect the wiring for the front wheel speed sensors.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 3

3

Verify that the correct outer constant velocity (CV) joints are installed on the vehicle. The front speed rings have 47 teeth and the rear speed rings have 29 teeth.

Are the correct outer CV joints installed?

--

Go to Step 5

Go to Step 4

4

Replace the incorrect outer CV joint.

Did you complete the replacement?

--

Go to Step 22

--

5

  1. Disconnect the wheel speed sensor harnesses from the wheel speed sensor connectors.
  2. Measure the wheel speed sensor resistance at the wheel speed sensor connector terminals.

Does the resistance measure within the specified range for both wheel speed sensors?

1280-1920 ohms

Go to Step 7

Go to Step 6

6

Replace the faulty wheel speed sensor.

Did you complete the replacement?

--

Go to Step 22

--

7

  1. Disconnect the antilock brake system (ABS) control module connector.
  2. Test each wheel speed sensor harness for a short circuit between its wires with a digital ohmmeter attached to the 2 terminals at the harness side of the wheel speed sensor connector.
  3. Test each wheel speed sensor harness wire for a short to ground from the connector terminals.

Is there any short circuit in either wheel speed sensor harness?

--

Go to Step 8

Go to Step 9

8

Repair the short circuit in the wiring or from a wiring harness to ground.

Did you complete the repair?

--

Go to Step 22

--

9

Test the continuity of the wiring in both front wheel speed sensor circuits between the ABS connector and the wheel speed sensor wheel speed sensor connector on each side of the vehicle.

    • The left side uses terminals 6 and 7 at the ABS connector.
    • The right side uses terminals 4 and 5 at the ABS connector.

Is the continuity good for both harnesses?

--

Go to Step 11

Go to Step 10

10

Repair the discontinuity found in the front wheel speed sensor harness.

Did you complete the repair?

--

Go to Step 22

--

11

  1. Visually inspect the wiring for the rear wheel speed sensors.
  2. Make sure that the wheel speed sensors are properly mounted and that the retaining bolts are properly tightened.

Is there any damage?

--

Go to Step 12

Go to Step 13

12

Repair or replace components as required.

Did you find and correct the condition?

--

Go to Step 22

--

13

Remove each wheel speed sensor from the rear knuckles and inspect the toothed ring through the wheel speed sensor mounting holes.

    • Inspect for any damaged or missing teeth.
    •  Inspect that the ring is properly positioned under the wheel speed sensor.

Is there any damage or other fault with either speed ring?

--

Go to Step 14

Go to Step 15

14

Replace the rear wheel hub with the proper unit.

Did you complete the replacement?

--

Go to Step 22

--

15

  1. Disconnect the rear wheel speed sensor harnesses from the wheel speed sensor connectors.
  2. Measure the wheel speed sensor resistance at the wheel speed sensor connector terminals.

Does the resistance measure within the specified range for both wheel speed sensors?

1280-1920 ohms

Go to Step 17

Go to Step 16

16

Replace the faulty wheel speed sensor.

Did you complete the replacement?

--

Go to Step 22

--

17

  1. Disconnect EBCM connector.
  2. Test each wheel speed sensor harness for a short circuit between its wires with a digital ohmmeter attached to the 2 terminals at the harness side of the wheel speed sensor connector.
  3. Test each wheel speed sensor harness wire for a short to ground from the connector terminals.

Is there any short circuit in either wheel speed sensor harness?

--

Go to Step 18

Go to Step 19

18

Repair the short circuit in the wiring or from a wire to ground.

Did you complete the repair?

--

Go to Step 22

--

19

Test the continuity of the wiring in both rear wheel speed sensor circuits between the ABS connector and the wheel speed sensor wheel speed sensor connector on each side of the vehicle.

    • The left side uses terminals 8 and 9 at the ABS connector.
    • The right side uses terminals 1 and 3 at the ABS connector.

Is continuity good for both harnesses?

--

Go to Step 21

Go to Step 20

20

Repair the discontinuity found in the rear wheel speed sensor wheel speed sensor harness or connector C110.

Did you complete the repair?

--

Go to Step 22

--

21

Replace the ABS unit.

Did you complete the replacement?

--

Go to Step 22

--

22
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK