Diagnostic Instructions

1. Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
2. Review Strategy Based Diagnosis for an overview of the diagnostic approach.
3. Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC C0035 04: Left Front Wheel Speed Sensor Circuit Open Circuit

DTC C1234: Left Rear Wheel Speed Sensor Circuit Open Circuit

DTC C0035 26: Left Front Wheel Speed Sensor Circuit Frequency too Low

DTC C1221: Left Front Wheel Speed Sensor Circuit Frequency too Low

DTC C0035 27: Left Front Wheel Speed Sensor Circuit Frequency too High

DTC C1225: Left Front Wheel Speed Sensor Circuit Frequency too High

DTC C0035 0E: Left Front Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C1207: Left Front Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C0035 1F: Left Front Wheel Speed Sensor Circuit Intermittent

DTC C1221: Left Front Wheel Speed Sensor Circuit Intermittent

DTC C0040 04: Right Front Wheel Speed Sensor Circuit Open Circuit

DTC C1233: Right Front Wheel Speed Sensor Circuit Open Circuit

DTC C0040 0E: Right Front Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C1208: Right Front Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C0040 1F: Right Front Wheel Speed Sensor Circuit Intermittent

DTC C1222: Right Front Wheel Speed Sensor Circuit Intermittent

DTC C0040 26: Right Front Wheel Speed Sensor Circuit Frequency too Low

DTC C1222: Right Front Wheel Speed Sensor Circuit Frequency too Low

DTC C0040 27: Right Front Wheel Speed Sensor Circuit Frequency too High

DTC C1226: Right Front Wheel Speed Sensor Circuit Frequency too High

DTC C0045 04: Left Rear Wheel Speed Sensor Circuit Open Circuit

DTC C1234: Left Rear Wheel Speed Sensor Circuit Open Circuit

DTC C0045 0E: Left Rear Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C1209: Left Rear Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C0045 1F: Left Rear Wheel Speed Sensor Circuit Intermittent

DTC C1223: Left Rear Wheel Speed Sensor Circuit Intermittent

DTC C0045 26: Left Rear Wheel Speed Sensor Circuit Frequency too Low

DTC C1223: Left Rear Wheel Speed Sensor Circuit Frequency too Low

DTC C0045 27: Left Rear Wheel Speed Sensor Circuit Frequency too High

DTC C1227: Left Rear Wheel Speed Sensor Circuit Frequency too High

DTC C0050 04: Right Rear Wheel Speed Sensor Circuit Open Circuit

DTC C1235: Right Rear Wheel Speed Sensor Circuit Open Circuit

DTC C0050 0E: Right Rear Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C1210: Right Rear Wheel Speed Sensor Circuit Resistance Below Threshold

DTC C0050 1F: Right Rear Wheel Speed Sensor Circuit Intermittent

DTC C1224: Right Rear Wheel Speed Sensor Circuit Intermittent

DTC C0050 26: Right Rear Wheel Speed Sensor Circuit Frequency too Low

DTC C1224: Right Rear Wheel Speed Sensor Circuit Frequency too Low

DTC C0050 27: Right Rear Wheel Speed Sensor Circuit Frequency too High

DTC C1228: Right Rear Wheel Speed Sensor Circuit Frequency too High

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Left Front Wheel Speed Sensor 12 Volt Reference	C0035 04,C1232	C0035 04,C1232	C0035 0E,C1207	C0035 1F,C1221, C0035 26,C1221 C0035 27,C1225
Left Front Wheel Speed Sensor Signal	C0035 04,C1232	C0035 04,C1232	C0035 0E,C1207	C0035 1F,C1221, C0035 26,C1221 C0035 27,C1225
Right Front Wheel Speed Sensor 12 Volt Reference	C0040 04,C1233	C0040 04,C1233	--	C0040 1F,C1222, C0040 26,C1222 C0040 27,C1226
Right Front Wheel Speed Sensor Signal	C0040 04,C1233	C0040 04,C1233	C0040 0E,C1208	C0040 1F,C1222, C0040 26,C1222 C0040 27,C1226
Left Rear Wheel Speed Sensor 12 Volt Reference	C0045 0E,C1209	C0045 04,C1234	--	C0045 1F,C1223, C0045 26,C1223 C0045 27,C1227
Left Rear Wheel Speed Sensor Signal	C0045 04,C1234	C0045 04,C1234	C0045 0E,C1209	C0045 1F,C1223, C0045 26,C1223 C0045 27,C1227
Right Rear Wheel Speed Sensor 12 Volt Reference	C0050 04,C1235	C0050 04,C1235	--	C0050 1F,C1224, C0050 26,C1224 C0050 27,C1228
Right Rear Wheel Speed Sensor Signal	C0050 04,C1235	C0050 04,C1235	C0050 0E,C1210	C0050 1F,C1224, C0050 26,C1224 C0050 27,C1228

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 1F,C1221, C0035 26,C1221 C0035 27,C1225
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 1F,C1222, C0040 26,C1222 C0040 27,C1226
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 1F,C1223, C0045 26,C1223 C0045 27,C1227
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 1F,C1224, C0050 26,C1224 C0050 27,C1228

Circuit/System Description

The wheel speed sensor (WSS) receives ignition voltage from the electronic brake control module (EBCM) and provides a DC square wave signal back to the module. As the wheel spins, the EBCM uses the frequency of the square wave signal to calculate the wheel speed.

Conditions for Running the DTC

Conditions for Setting the DTC

C0035 04 - C0050 04, C0035 0E - C0050 0E,C1232 - C1235, or C1207 - C1210

A short to voltage, short to ground or an open/high resistance is detected on a wheel speed sensor circuit.

C0035 26 - C0050 26, C0035 27 - C0050 27, C0035 1F - C0050 1F, C1221 - C1224, C1225 - C1228, or C1221 - C1224

Conditions for Setting the DTC

Actions Taken when the DTC Sets

Conditions for Clearing the DTC

Diagnostic Aids

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:

1. 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).
2. Test drive the vehicle over various road surfaces: bumps, turns, etc., above 40 km/h (25 mph) for at least 30 seconds.
3. Rinse the area thoroughly when completed.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS Description and Operation

Electrical Information Reference

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

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition ON, test for less than 1 volt between the 12-volt reference circuit terminal 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.

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

•	LF Sensor circuit terminal 29

•	RF Sensor circuit terminal 6

•	LR Sensor circuit terminal 5

•	RR Sensor circuit terminal 2

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

4. Ignition OFF, test for infinite resistance between the 12-volt reference terminal of the appropriate sensor circuit 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 12- volt reference circuit for a short to ground.

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

•	LF Sensor circuit terminal 29

•	RF Sensor circuit terminal 6

•	LR Sensor circuit terminal 5

•	RR Sensor circuit terminal 2

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

6. Ignition OFF, disconnect the harness connector at the appropriate WSS.
7. Test for less than 2 ohms between the appropriate 12-volt reference circuit terminals listed below.

•	LF Sensor circuit terminal 28 at the EBCM harness connector, and terminal 2 at the WSS harness connector

•	RF Sensor circuit terminal 17 at the EBCM harness connector, and terminal 2 at the WSS harness connector

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

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

⇒	If greater than the specified range, test the 12-volt reference circuit for an open or high resistance.

8. Test for less than 2 ohms between the appropriate signal circuit terminals listed below.

•	LF Sensor circuit terminal 29 at the EBCM harness connector, and terminal 1 at the WSS harness connector

•	RF Sensor circuit terminal 6 at the EBCM harness connector, and terminal 1 at the WSS harness connector

•	LR Sensor circuit terminal 5 at the EBCM harness connector, and terminal A at the WSS harness connector

•	RR Sensor circuit terminal 2 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.

9. If all circuits test normal, replace the appropriate wheel speed sensor. If the DTC resets replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.