DTC C0035-C0050. Cadillac STS 2009

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2009 🢒 STS 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC C0035-C0050

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC C0035 02 : Left Front Wheel Speed Sensor Circuit Short to Ground

DTC C0035 05 : Left Front Wheel Speed Sensor Circuit Short to Battery or Open

DTC C0035 0F : Left Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0035 18 : Left Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0040 02 : Right Front Wheel Speed Sensor Circuit Short to Ground

DTC C0040 05 : Right Front Wheel Speed Sensor Circuit Short to Battery or Open

DTC C0040 0F : Right Front Wheel Speed Sensor Circuit Erratic Signal

DTC C0040 18 : Right Front Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0045 02 : Left Rear Wheel Speed Sensor Circuit Short to Ground

DTC C0045 05 : Left Rear Wheel Speed Sensor Circuit Short to Battery or Open

DTC C0045 0F : Left Rear Wheel Speed Sensor Circuit Erratic Signal

DTC C0045 18 : Left Rear Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

DTC C0050 02 : Right Rear Wheel Speed Sensor Circuit Short to Ground

DTC C0050 05 : Right Rear Wheel Speed Sensor Circuit Short to Battery or Open

DTC C0050 0F : Right Rear Wheel Speed Sensor Circuit Erratic Signal

DTC C0050 18 : Right Rear Wheel Speed Sensor Circuit Signal Amplitude Less Than Minimum

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Left Front Wheel Speed Sensor Signal	C0035 02	C0035 05	C0035 05	C0035 0F, C0035 18
Left Front Wheel Speed Sensor Low Reference	C0035 02	C0035 05	C0035 05	C0035 0F, C0035 18
Right Front Wheel Speed Sensor Signal	C0040 02	C0040 05	C0040 05	C0040 0F, C0040 18
Right Front Wheel Speed Sensor Low Reference	C0040 02	C0040 05	C0040 05	C0040 0F, C0040 18
Left Rear Wheel Speed Sensor Signal	C0045 02	C0045 05	C0045 05	C0045 0F, C0045 18
Left Rear Wheel Speed Sensor Low Reference	C0045 02	C0045 05	C0045 05	C0045 0F, C0045 18
Right Rear Wheel Speed Sensor Signal	C0050 02	C0050 05	C0050 05	C0050 0F, C0050 18
Right Rear Wheel Speed Sensor Low Reference	C0050 02	C0050 05	C0050 05	C0050 0F, C0050 18

Component

Condition

DTCs

Left Front Wheel Speed Sensor

•	Physical damage

•	Debris on the wheel speed sensor or the encoder ring

•	Loose or improperly mounted sensor

•	Loose or worn wheel bearing

•	Air gap between the wheel speed sensor and the encoder ring too large

C0035 0F, C0035 18

Right Front Wheel Speed Sensor

•	Physical damage

•	Debris on the wheel speed sensor or the encoder ring

•	Loose or improperly mounted sensor

•	Loose or worn wheel bearing

•	Air gap between the wheel speed sensor and the encoder ring too large

C0040 0F, C0040 18

Left Rear Wheel Speed Sensor

•	Physical damage

•	Debris on the wheel speed sensor or the encoder ring

•	Loose or improperly mounted sensor

•	Loose or worn wheel bearing

•	Air gap between the wheel speed sensor and the encoder ring too large

C0045 0F, C0045 18

Right Rear Wheel Speed Sensor

•	Physical damage

•	Debris on the wheel speed sensor or the encoder ring

•	Loose or improperly mounted sensor

•	Loose or worn wheel bearing

•	Air gap between the wheel speed sensor and the encoder ring too large

C0050 0F, C0050 18

Circuit/System Description

As the wheel spins, the wheel speed sensor (WSS) produces an alternating current (AC) signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

Conditions for Setting the DTC

C0035 02-C0050 02

•	Ignition ON.

•	A short to ground is detected on the wheel speed sensor circuits.

C0035 052-C0050 05

•	Ignition ON.

•	A short to voltage or an open is detected on the wheel speed sensor circuits.

C0035 18-C0050 18

•	Ignition ON.

•	An erratic signal output of the wheel speed sensor is detected.

•	Physical damage to the wheel speed sensor or EBCM.

•	Debris on the wheel speed sensor or the encoder ring.

•	Loose or improperly mounted sensor.

•	Air gap between the wheel speed sensor and encoder ring too large.

C0035 0F-C0050 0F

•	Ignition ON

•	Physical damage to the wheel speed sensor or EBCM.

•	Damage to the cable harness to wheel speed sensor.

•	Loose or improperly mounted sensor.

Actions Taken when the DTC Sets

•	The EBCM disables the antilock brake system (ABS), the traction control system (TCS), and the electronic stability control (ESC), for the duration of the ignition cycle.

•	A DIC message and/or a warning indicator may be displayed.

Conditions for Clearing the DTC

•	A current DTC clears when the diagnostic runs and passes.

•	A history DTC clears after 40 consecutive ignition cycles.

Diagnostic Aids

•	Inspect the back of the wheel bearing on the encoder surface for metal debris that could cause an erratic reading with the sensor. Do not use a magnet to clean the debris, or damage to the encoder ring may occur.

•	If 2 or more wheel speed sensors are inoperative diagnose each wheel speed sensor individually.

•	An ECE 13 response may be required, after repairs are made, ignition cycled, and DTCs are cleared, operate the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, and the EBCM will turn off the ABS indicator.

If the customer comments that the ABS indicator is ON only during moist environmental conditions: rain, snow, vehicle wash, etc., inspect the wheel speed sensor wiring for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:

Spray the suspected area with a 5 percent saltwater solution. To create a 5 percent saltwater solution, add 2 teaspoons of salt to 8 fl oz of water (10 g of salt to 200 ml of water).
Test drive the vehicle over various road surfaces: bumps, turns, etc., above 40 km/h (25 mph) for at least 30 seconds.
Rinse the area thoroughly when completed.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Observe the scan tool Wheel Speed Sensor parameter. The reading should be the same speed on all sensors when driving in a straight line at a speed greater than 20 km/h (13 mph).

Circuit/System Testing

Important: Component Testing is performed before Circuit Testing when diagnosing wheel speed sensors.

Ignition OFF, disconnect the harness connector at the EBCM.
Ignition ON, test for less than 1 volt between the low reference circuit terminals of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal 28

•	RF Sensor circuit terminal 17

•	LR Sensor circuit terminal 4

•	RR Sensor circuit terminal 3

⇒	If greater than the specified range, test the low reference circuit for a short to voltage.

Test for less than 1 volt between the signal circuit terminals of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal 27

•	RF Sensor circuit terminal 30

•	LR Sensor circuit terminal 16

•	RR Sensor circuit terminal 15

⇒	If greater than the specified range, test the signal circuit for a short to voltage.

Ignition OFF, test for infinite resistance between the low reference terminals of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal 28

•	RF Sensor circuit terminal 17

•	LR Sensor circuit terminal 4

•	RR Sensor circuit terminal 3

⇒	If less than the specified value, test the low reference circuit for a short to ground.

Test for infinite resistance between the following signal circuit terminals of the appropriate sensor listed below and ground.

•	LF Sensor circuit terminal 27

•	RF Sensor circuit terminal 30

•	LR Sensor circuit terminal 16

•	RR Sensor circuit terminal 15

⇒	If less than the specified value, test the signal circuit for a short to ground.

Ignition OFF, disconnect the harness connector at the wheel speed sensor.
Test for less than 2 ohms between the appropriate signal circuit terminals listed below.

•	LF Sensor circuit terminals 28 at the EBCM harness connector, and terminal A at the WSS harness connector

•	RF Sensor circuit terminals 17 at the EBCM harness connector, and terminal A at the WSS harness connector

•	LR Sensor circuit terminals 4 at the EBCM harness connector, and terminal A at the WSS harness connector

•	RR Sensor circuit terminals 3 at the EBCM harness connector, and terminal A at the WSS harness connector

⇒	If greater than the specified range, test the signal circuit for an open or high resistance.

Test for less than 2 ohms between the appropriate low reference circuit terminals listed below.

•	LF Sensor circuit terminals 27 at the EBCM harness connector, and terminal B at the WSS harness connector

•	RF Sensor circuit terminals 30 at the EBCM harness connector, and terminal B at the WSS harness connector

•	LR Sensor circuit terminals 16 at the EBCM harness connector, and terminal B at the WSS harness connector

•	RR Sensor circuit terminals 15 at the EBCM harness connector, and terminal B at the WSS harness connector

⇒	If greater than the specified range, test the low reference circuit for an open or high resistance.

If all circuits test normal, test or replace the wheel speed sensor (WSS). If the DTC resets, replace the EBCM.

Component Testing

Ignition OFF, disconnect the harness connector at the appropriate wheel speed sensor.
Test for 850-1350 ohms between the signal terminal A and the low reference signal terminal B. During the test, check for an intermittent circuit condition by gentle moving the wheel speed sensor pigtail harness.

⇒	If not within the specified range, replace the wheel speed sensor.

Test for infinite resistance between each terminal and the steering knuckle. Reverse the test leads, test for infinite resistance between each terminal and the steering knuckle again.

⇒	If less than the specified value, replace the appropriate wheel speed sensor.

Spin the wheel while monitoring the voltage between the signal terminal A and the low reference terminal B. The voltage should be greater than 100 mV AC.

⇒	If less than the specified range, replace the wheel speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Front Wheel Bearing and Hub Replacement

•	Rear Wheel Bearing and Hub Replacement

•	Control Module References for EBCM replacement, setup, and programming