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Home >> Mercury >> 2009 >> Milan AWD V6-3.0L >> Repair and Diagnosis >> Brakes and Traction Control >> Antilock Brakes / Traction Control Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test D: DTCs C1233, C1234, C1235 and C1236

Pinpoint Test D: DTCs C1233, C1234, C1235 and C1236




Anti-Lock Control

Pinpoint Tests

Pinpoint Test D: DTCs C1233, C1234, C1235 and C1236

Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number

Normal Operation

The wheel speed sensor and sensor ring generate a square wave signal to the ABS module that is proportional to the wheel speed. The ABS module compares the wheel speed inputs from all the wheel speed sensors to determine an impending wheel lockup.

DTC C1233-DTC C1236:





This pinpoint test is intended to diagnose the following:
- Mismatched tire sizes
- Wheel speed sensor ring (part of the wheel bearing and hub assembly)
- Wheel speed sensor
- ABS module



PINPOINT TEST D: DTCs C1233, C1234, C1235 AND C1236

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

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D1 CHECK THE DTCs FROM THE SELF-TEST


- Using the recorded results from the ABS module self-test:
- Are DTCs C1145, C1155, C1165 or C1175 present?

Yes
Go To Pinpoint Test C. Pinpoint Test C: DTCs C1145, C1155, C1165 and C1175

No
GO to D2.

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D2 MONITOR THE WHEEL SPEED SENSOR PIDs


- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS.
- Using the scan tool, monitor the following PIDs while driving the vehicle at a constant speed.
- Left front wheel speed sensor (LF_WSPD)
- Right front wheel speed sensor (RF_WSPD)
- Left rear wheel speed sensor (LR_WSPD)
- Right rear wheel speed sensor (RR_WSPD)
- Are all wheel speed sensor PID values similar?

Yes
CLEAR the DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If DTC C1233, C1234, C1235 or C1236 is present, GO to D12.

No
If the Active Wheel Speed Sensor Tester is available, GO to D3.

If the Active Wheel Speed Sensor Tester is not available, GO to D6.

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D3 CHECK THE ABS MODULE OUTPUT USING THE ACTIVE WHEEL SPEED SENSOR TESTER


NOTE: The front wheel speed sensor electrical connectors are located behind the wheel well splash shields. The rear wheel speed sensor electrical connectors are located under the rear seat cushion.

- Ignition OFF.
- Disconnect: Suspect Wheel Speed Sensor.
- Connect the Active Wheel Speed Sensor Tester to the wheel speed sensor connectors.
- Ignition ON.
- Select the correct system polarity on the tester and turn the tester power switch to the ON position.
- Is the module output LED illuminated?

Yes
GO to D5.

No
GO to D4.

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D4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN


NOTE: Both circuits must be checked for each DTC.

NOTE: The degas bottle may need to be positioned aside to access the ABS module connector.

- Ignition OFF.
- Disconnect: ABS Module C135.
- Measure the resistance between ABS module C135, harness side and the suspect wheel speed sensor connector, harness side as indicated in the following chart:





- Are the resistances less than 5 ohms?

Yes
GO to D12.

No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.

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D5 CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE ACTIVE WHEEL SPEED SENSOR TESTER


- Raise the suspect wheel until it can spin freely. Refer to Maintenance/Service and Repair.
- While monitoring the Active Wheel Speed Sensor Tester, slowly spin the suspect wheel.
- Do the sensor output LEDs illuminate and flash and is the current overload LED not illuminated?

Yes
INSPECT the wheel speed sensor tone ring for damage and looseness. INSTALL new components as necessary. If the tone ring is OK, the concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

No
If the current level LED is not illuminated and the sensor output LEDs do not illuminate or if the current level LED is illuminated red, INSTALL a new wheel speed sensor. For the front wheel speed sensor, REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front. For the rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear, Front Wheel Drive (FWD) or Wheel Speed Sensor - Rear, All Wheel Drive (AWD) Wheel Speed Sensor - Rear, All Wheel Drive (AWD). CLEAR the DTCs. REPEAT the self-test.

If the current level LED is not illuminated and the sensor output LEDs illuminate green, but do not flash, INSPECT the wheel speed sensor tone ring and INSTALL new if necessary. If the tone ring is OK, INSTALL a new wheel speed sensor. For the front wheel speed sensor, REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front. For the rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear, Front Wheel Drive (FWD) or Wheel Speed Sensor - Rear, All Wheel Drive (AWD) Wheel Speed Sensor - Rear, All Wheel Drive (AWD). CLEAR the DTCs. REPEAT the self-test.

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D6 CHECK FOR CORRECT ABS MODULE OUTPUT


NOTE: The front wheel speed sensor electrical connectors are located behind the wheel well splash shields. The rear wheel speed sensor electrical connectors are located under the rear seat cushion.

- Ignition OFF.
- Disconnect: Suspect Wheel Speed Sensor.
- Ignition ON.
- For DTC C1233, measure the voltage between:
- RF wheel speed sensor C160-1, circuit VCA05 (GY/VT), harness side and RF wheel speed sensor C160-2, circuit RCA19 (VT), harness side.




- For DTC C1234, measure the voltage between:
- LF wheel speed sensor C150-1, circuit VCA03 (VT/WH), harness side and LF wheel speed sensor C150-2, circuit RCA17 (YE), harness side.




- For DTC C1235, measure the voltage between:
- RR wheel speed sensor C426-3, circuit VCA06 (WH/OG), harness side and RR wheel speed sensor C426-1, circuit RCA20 (BN), harness side.




- For DTC C1236, measure the voltage between:
- LR wheel speed sensor C440-3, circuit VCA04 (BU/OG), harness side and LR wheel speed sensor C440-1, circuit RCA18 (BN/GN), harness side.




- Are the voltages greater than 10 volts?

Yes
INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front, Wheel Speed Sensor - Rear, All Wheel Drive (AWD) Wheel Speed Sensor - Rear, All Wheel Drive (AWD) or Wheel Speed Sensor - Rear, Front Wheel Drive (FWD) . CLEAR the DTCs. REPEAT the self-test.

No
GO to D7.

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D7 INSPECT THE WHEEL SPEED SENSOR MOUNTING


- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Maintenance/Service and Repair.
- Inspect the suspect wheel speed sensor(s) for looseness.
- Is the wheel speed sensor(s) loose?

Yes
TIGHTEN the wheel speed sensor bolt to specification. REFER to Specifications.

No
GO to D8.

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D8 INSPECT THE WHEEL SPEED SENSOR FOR DAMAGE


- NOTE: Inspect the wheel speed sensor wire carefully with a good light source. Failure to verify damage in the wheel speed sensor wire can lead to unnecessary installation of a new component.
- Inspect the suspect wheel speed sensor(s) for general damage.
- Is the wheel speed sensor(s) OK?

Yes
GO to D9.

No
INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front, Wheel Speed Sensor - Rear, All Wheel Drive (AWD) Wheel Speed Sensor - Rear, All Wheel Drive (AWD) or Wheel Speed Sensor - Rear, Front Wheel Drive (FWD) . CLEAR the DTCs. REPEAT the self-test.

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D9 INSPECT THE WHEEL SPEED SENSOR RING FOR DAMAGE


- Remove the suspect wheel speed sensor(s). Refer to Wheel Speed Sensor - Front Wheel Speed Sensor - Front, Wheel Speed Sensor - Rear, All Wheel Drive (AWD) Wheel Speed Sensor - Rear, All Wheel Drive (AWD) or Wheel Speed Sensor - Rear, Front Wheel Drive (FWD) .
- Inspect the suspect wheel speed sensor ring(s) for damage or missing teeth. Rotate the wheel to verify that no teeth are missing.
- Is the wheel speed sensor ring(s) OK?

Yes
GO to D10.

No
INSTALL new wheel bearing and wheel hubs as necessary.

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D10 INSPECT THE WHEEL BEARINGS FOR DAMAGE


- Inspect the wheel bearings for damage.
- Are the wheel bearings OK?

Yes
GO to D11.

No
INSTALL new wheel bearing and wheel hubs as necessary.

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D11 RECHECK THE WHEEL SPEED SENSOR PIDs


- Connect: Suspect Wheel Speed Sensor.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS.
- Using the scan tool, monitor the following PIDs while driving the vehicle at a constant speed.
- Left front wheel speed sensor (LF_WSPD)
- Right front wheel speed sensor (RF_WSPD)
- Left rear wheel speed sensor (LR_WSPD)
- Right rear wheel speed sensor (RR_WSPD)
- Are all wheel speed sensor PID values similar?

Yes
The system is operating correctly at this time. The concern may have been caused by a loose or damaged wheel speed sensor, a damaged wheel speed sensor ring or a damaged wheel bearing.

No
GO to D9.

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D12 CHECK FOR CORRECT ABS MODULE OPERATION


- Ignition OFF.
- Disconnect: ABS Module C135.
- Check the connector for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: ABS Module C135.
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSPECT the wheel speed sensor tone ring for damage and looseness. INSTALL new components as necessary. If the tone ring is OK, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module Service and Repair CLEAR the DTCs. REPEAT the self-test.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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