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Home >> Dodge or Ram Truck >> 2005 >> RAM 3500 Truck 2WD L6-5.9L DSL Turbo VIN C >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> Antilock Brake System (ABS) >> 21 - Right Front Sensor Open

21 - Right Front Sensor Open

RIGHT FRONT SENSOR OPEN-21





For a complete wiring diagram, refer to Wiring Diagram Information.

When Monitored
Ignition on.

Set Condition
The CAB detects an open in the wheel speed sensor circuit

Possible Causes
- INTERMITTENT RIGHT FRONT WHEEL SPEED SENSOR DTC
- RIGHT FRONT WHEEL SPEED SENSOR (+) CIRCUIT SHORT TO GROUND
- RIGHT FRONT WHEEL SPEED SENSOR (-) CIRCUIT SHORT TO GROUND
- RIGHT FRONT WHEEL SPEED SENSOR (+) CIRCUIT OPEN
- RIGHT FRONT WHEEL SPEED SENSOR (-) CIRCUIT OPEN
- TONE WHEEL
- EXCESSIVE RIGHT FRONT WHEEL SPEED SENSOR AIR GAP
- WHEEL BEARING
- RIGHT FRONT WHEEL SPEED SENSOR
- CONTROL ANTI-LOCK BRAKE

Diagnostic Test
1. DTC IS ACTIVE
Turn the ignition on.
With the DRBIII (R) clear DTCs.
Turn the ignition off.
Turn the ignition on.
With the DRBIII (R) select View DTCs.

Does the DRBIII (R) display the DTC?
Yes >> Go To 2
No >> Go To 12

2. WHEEL SPEED SENSOR INSPECTION
Turn the ignition off.
Inspect the Wheel Speed Sensor for proper mounting.
Inspect the Wheel Speed Sensor harness and connector.
Inspect the Wheel Speed Sensor for excessive debris on the sensor.

Were any problems found?
Yes >> Repair as necessary in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 3

3. TONE WHEEL DAMAGED/MISSING
Inspect the Tone Wheel in accordance with the Service Information.

NOTE: The Tone Wheel Teeth should be perfectly square, not bent or nicked.

Were any problems found?
Yes >> Replace the Tone Wheel in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 4

4. EXCESSIVE WHEEL SPEED SENSOR AIR GAP
Measure the Wheel Speed Sensor Air Gap in accordance with the Service Information.

Were any problems found?
Yes >> Repair as necessary in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 5

5. WHEEL BEARING LOOSE/BINDING
Inspect the wheel bearings for excessive run out or improper clearance in accordance with the Service Information.

Were any problems found?
Yes >> Repair as necessary in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 6

6. RIGHT FRONT WHEEL SPEED SENSOR (+) CIRCUIT SHORTED TO GROUND





Turn the ignition off. Disconnect the Right Front Wheel Speed Sensor harness connector.
Disconnect the Controller Anti-lock Brake harness connector.

NOTE: Check connector - Clean/repair as necessary. Measure the resistance between the Right Front Wheel Speed Sensor (+) circuit and ground.

Is the resistance above 5.0 ohms?
Yes >> Go To 7
No >> Repair the Right Front Wheel Speed Sensor (+) circuit for a short to ground.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

7. RIGHT FRONT WHEEL SPEED SENSOR (-) CIRCUIT SHORTED TO GROUND





Measure the resistance between the Right Front Wheel Speed Sensor (-) circuit and ground.

Is the resistance above 5.0 ohms?
Yes >> Go To 8
No >> Repair the Right Front Wheel Speed Sensor (-) circuit for a short to ground.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

8. RIGHT FRONT WHEEL SPEED SENSOR (+) CIRCUIT OPEN





Measure the resistance of the Right Front Wheel Speed Sensor (+) circuit.

Is the resistance below 5.0 ohms?
Yes >> Go To 9
No >> Repair the open Right Front Wheel Speed Sensor (+) circuit.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

9. RIGHT FRONT WHEEL SPEED SENSOR (-) CIRCUIT OPEN





Measure the resistance of the Right Front Wheel Speed Sensor (-) circuit.

Is the resistance below 5.0 ohms?
Yes >> Go To 10
No >> Repair the open Right Front Wheel Speed Sensor (-) circuit.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

10. RIGHT FRONT WHEEL SPEED SENSOR
Turn the ignition off.
Connect the Right Front Wheel Speed Sensor harness connector.
Measure the resistance between the Right Front Wheel Speed Sensor (+) circuit and Right Front Wheel Speed Sensor (-) circuit at the Controller Anti-lock Brake harness connector.

NOTE: The resistance should be approximately 1600-2300 ohms at 76 degrees F.

Is the resistance within the noted range?
Yes >> Go to 11
No >> Replace the Right Front Wheel Speed Sensor in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

11. CONTROLLER ANTI-LOCK BRAKE
Turn the ignition off.
Inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?
Yes >> Repair as necessary in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Replace the Controller Anti-lock Brake in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test

12. WIRING HARNESS INSPECTION
Turn the ignition off.

NOTE: Towing the vehicle with ignition ON may set this DTC.
Inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?
Yes >> Repair as necessary in accordance with the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Test Complete.
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