GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Prizm 🢒 DTC 🢒 DTC C0050 RR Wheel Speed Circuit Malfunction

Object Number: 396377 Size: SF
ABS Components
Cell 44: Wheel Speed Sensors
Handling ESD Sensitive Parts Notice

Circuit Description

The Electronic Brake Control Module (EBCM) receives right rear wheel speed sensor voltage signal through terminal 15 and terminal 16. As a toothed reluctor wheel ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce a small AC voltage signal. This signal's frequency is proportional to the wheel speed.

Conditions for Setting the DTC
    • DTC C0050 will set when the EBCM detects an open, a short to voltage, or a short to ground.
    • DTC C0050 can be set anytime.

Action Taken When the DTC Sets
    • A malfunction DTC stores
    • The ABS disables
    • The ABS warning indicator turns 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

Inspect for the following when diagnosing this part of the Antilock Brake System (ABS):

    • Faulty electrical circuits (open and or high resistance short to voltage or short to ground) between the right rear wheel speed sensor and the EBCM
    • Faulty right rear wheel speed sensor (out of range resistance)

An intermittent malfunction is most likely caused by a poor connection rubbed thorough wire insulation or a wire that is broken inside the insulation.

If the customer comments reflect that the ABS indicator lamp is ON only during humid conditions (rain, snow, vehicle wash), thoroughly inspect the right rear wheel speed sensor circuitry for signs of water intrusion.

Thoroughly inspect any circuitry that is suspected or causing the intermittent complaint for the following conditions:

    • Backed-out terminals
    • Improper mating
    • Broken locks
    • Improperly formed or damaged terminals
    • Poor terminal to wiring connections
    • Physical damage to the wiring harness

       Important: Wheel speed sensor resistance increases with an increase in sensor temperature.

When measuring for a short to ground in a wheel speed sensor wiring circuit, manually switch the J 39200 (Digital Multimeter) to the Meg-Ohms range. This will ensure a high resistance short to ground can be found. See J 39200 owners manual.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests for wheel speed sensor internal resistance for proper values.

    2.

  2. Tests for wheel speed sensor circuits shorted together.

    3.

  3. Tests for a shorted to ground in the BRN wire.

    4.

  4. Tests for a short to ground in the YEL wire.

    5.

  5. Tests for a short to voltage in the BRN wire.

    6.

  6. Tests for a short to voltage in the YEL wire.

    7.

  7. Tests for an open or high resistance in the BRN wire.

    8.

  8. Tests for an open or high resistance in the YEL wire.

    9.

  9. Tests for a poor connections at electrical connectors.

    10.

  10. Determines whether the condition is intermittent and not due to a malfunctioning EBCM.

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2

  1. Remove the rear seatback. Refer Rear Seat Back Replacement in Seats.
  2. Disconnect the right rear wheel speed sensor electrical connector.
  3. Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal A and terminal B (sensor side).

Is the resistance within the specified range?

1120-2520 ohms

Go to Step 3

Go to Step 12

3

  1. Disconnect the Electronic Brake Control Module (EBCM) electrical connector.
  2. Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal A and terminal B (harness side).

Is the resistance equal to the specified value?

OL

(Infinite)

Go to Step 4

Go to Step 13

4

Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal A (harness side) and ground.

Is the resistance equal to the specified value?

OL

(Infinite)

Go to Step 5

Go to Step 14

5

Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal B (harness side) and ground.

Is the resistance equal to the specified value?

OL

(Infinite)

Go to Step 6

Go to Step 15

6

  1. Turn the ignition switch to the ON position.
  2. Use J 39200 (DMM) in order to measure the voltage between the right rear wheel speed sensor connector terminal A (harness side) and ground.

Is the voltage within the specified range?

0-1 V

Go to Step 7

Go to Step 16

7

Use J 39200 (DMM) in order to measure the voltage between the right rear wheel speed sensor connector terminal B (harness side) and ground.

Is the voltage within the specified range?

0-1 V

Go to Step 8

Go to Step 17

8

Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal A (harness side) and the EBCM electrical connector terminal 15 (harness side).

Is the resistance within the specified range?

0-2 ohms

Go to Step 9

Go to Step 18

9

Use J 39200 (DMM) in order to measure the resistance between the right rear wheel speed sensor connector terminal B (harness side) and the EBCM electrical connector terminal 16 (harness side).

Is the resistance within the specified range?

0-2 ohms

Go to Step 10

Go to Step 19

10

  1. Inspect the EBCM electrical connector and the right rear wheel speed sensor connector for the following conditions:
    2. • Poor terminal contact
    • Corrosion
    • Damage
  2. Repair as necessary. Refer to Rear Wheel Speed Sensor Replacement .

Is the action complete?

--

Go to Step 11

--

11

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the right rear wheel speed sensor electrical connector.
  3. Reconnect the EBCM electrical connector.
  4. Turn the ignition switch to the ON position.
  5. Connect a scan tool to the OBD2 Data Link Connector (DLC).
  6. Select Diagnostic Trouble Codes (DTC) on the scan tool.
  7. Select DTC Information on the scan tool.
  8. Select Current DTC on the scan tool.

Is DTC C0050 set as a Current DTC?

--

Go to Step 21

Go to Step 20

12

Replace the right rear wheel speed sensor. Refer to Rear Wheel Speed Sensor Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

13

Repair the short between the YEL and BRN wires. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

14

Repair short to ground in the BRN wire. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

15

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

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

16

Repair short to voltage in the YEL wire. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

17

Repair short to voltage in the YEL wire. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

18

Repair an open or high resistance in the BRN wire. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

19

Repair an open or high resistance in the YEL wire. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--

20

A malfunction is not present at this time. Refer to Diagnostic Aids for additional information regarding this DTC.

Is the action complete?

--

Go to Diagnostic System Check - ABS

--

21
  1. Test the electrical harness between the EBCM and the right rear wheel speed sensor for possible short to ground, short to voltage, or open in the YEL and/or BRN wires.
  2. Inspect the EBCM electrical connector for poor terminal contact.
  3. Repair wiring as necessary. Refer to Wiring Repairs in Wiring Systems.
  4. If the wiring is OK, replace the brake pressure modulator valve assembly. Refer to Brake Pressure Modulator Valve Assembly Replacement .

Is the repair complete?

--

Go to Diagnostic System Check - ABS

--