Archived abs help

[KMireiter]

I have a 1999 dodge 3500 4x4 with all wheel abs. On the scanner the left front wheel loses signal while driving down the road . I have changed the hub, abs wheel speed sensor , and the abs pump and controler and still the same thing . I have also ruled out the wiring by hard wiring the abs wheel speed sensor to the abs module and still loses signal. When it loses sigal while driving if at the right time when it is gone and you try to stop the pedal goes to the floor and cant stop

 

[JLandry]

Are you using a Chrysler DRBIII to check for trouble codes?



Have you tried resetting the CAB using a DRBIII?



Are you getting an ABS warning lamp on the instrument cluster?



Read through the following trouble shooting steps from the 1999 Chassis Diagnostic manual and see if anything jumps out at you. At a minimum I'd take the resistance measurements they specify to verify the wiring continuity.



Symptom: NO SIGNAL FROM LEFT FRONT SENSOR



When Monitored and Set Condition: NO SIGNAL FROM LEFT FRONT SENSOR



When Monitored:

Set Condition: 1. Speed greater than 13km/h (8mph) from one sensor.

2. No ABS activity.

3. No evidence of drivetrain accel detected.

4. No open sensor DTC.

5. No other DTC tests run.

6. Indicated speed at sensor under 6km/h (4mph).

7. Criteria 1-6 satisfied for 5 checks



POSSIBLE CAUSES:



CAB CONNECTOR OBSERVABLE DEFECT

LEFT FRONT WSS (+) CIRCUIT OPEN

LEFT FRONT WSS (+) CIRCUIT SHORTED TO GROUND

LEFT FRONT WSS (-) CIRCUIT OPEN

LEFT FRONT WSS 2-WAY CONNECTOR OBSERVABLE DEFECT

LEFT FRONT WSS DEFECTIVE

LEFT FRONT WSS OBSERVABLE DEFECT

WSS WIRING HARNESS OBSERVABLE DEFECT



TEST 78

Ignition Off

Note: Whenever a WSS - related trouble code is detected, a thorough visual inspection of the wiring harness must be performed.

Inspect the Wiring Harness and the following list of Connectors of the WSS Circuits and any related harnesses for any broken, bent, pushed out, or corroded terminals, or any chafed, pierced, or partially broken wires.

Rear Sensor (located on top of Differential); Chassis to Rear Sensor (Right Frame Rail just ahead of Axle); Chassis to Head Lamp/Dash Harness (Right Frame Rail near Transmission); ABS Module (under Hood left side under Battery Tray). Left Front Sensor (located below the ABS Module at Left Fender Side Shield); Right Front Sensor (above the Right Control Arm at Right Fender Side Shield).

Note: Refer to any hotlines or technical service bulletins that may apply.

Were any problems found?

Yes → Repair as necessary.

No → Go To 79



TEST 79

Ignition Off

Note: Trouble code sets when an intermittent Wheel Speed Signal is being

received at the CAB between 13 - 32 KM/H (8 - 20 MPH).

Inspect the Left Front WSS.

Is the WSS okay?

Yes → Go To 80

No → Repair as necessary.

Perform ABS Verification Test VER-1A.



TEST 80

Ignition Off

Disconnect the CAB Connector C2.

Note: Check connectors - Clean/repair as necessary.

Using an Ohmmeter, measure the resistance of the Left Front Wheel Speed Sensor Circuit at CAB Connector C2.

Is the resistance between 1000 - 1250 ohms for 2WD, or 945 - 1155 ohms for 4WD?

Yes → Refer to symptom CAB FAILURE VERIFICATION.

No → Go To 81



TEST 81

Ignition Off

Disconnect the Left Front WSS 2-Way Connector.

Note: Check connectors - Clean/repair as necessary.

Inspect all Terminals.

Is any Terminal damaged, pushed out or miswired?

Yes → Repair as necessary.

Perform ABS Verification Test VER-1A.

No → Go To 82



TEST 82

Ignition Off

Disconnect the Left Front WSS 2-Way Connector.

Note: Check connectors - Clean/repair as necessary.

Using an Ohmmeter, measure the resistance of the Left Front WSS Circuit at the 2-Way Connector.

Is the resistance between 1000 - 1250 ohms for 2WD, or 945 - 1155 ohms for 4WD?

Yes → Go To 83

No → Replace the Left Front WSS.

Perform ABS Verification Test VER-1A.



TEST 83

Ignition Off

Disconnect the CAB Connector C2.

Note: Check connectors - Clean/repair as necessary.

Inspect all Terminals.

Is any Terminal damaged, pushed out, or miswired?

Yes → Repair as necessary.

Perform ABS Verification Test VER-1A.

No → Go To 84



TEST 84

Ignition Off

Disconnect the CAB Connector C2.

Note: Check connectors - Clean/repair as necessary.

Disconnect the Left Front WSS 2-Way Connector.

Note: Check connectors - Clean/repair as necessary.

Using an Ohmmeter, measure the resistance of the Left Front Wheel Speed Sensor (-) Circuit between the CAB and the Sensor.

Is the resistance below 5 ohms?

Yes → Go To 85

No → Repair the open WSS (-) Circuit.

Perform ABS Verification Test VER-1A.



TEST 85

Ignition Off

Disconnect the CAB Connector C2.

Note: Check connectors - Clean/repair as necessary.

Using an Ohmmeter, measure LF Wheel Speed Sensor (+) Circuit.

Is the resistance below 20K ohms?

Yes → Repair the WSS (+) Circuit for a short to ground.

Perform ABS Verification Test VER-1A.

No → Go To 86



TEST 86

Ignition Off

Disconnect the CAB Connector C2.

Note: Check connectors - Clean/repair as necessary.

Disconnect the Left Front WSS 2-Way Connector.

Note: Check connectors - Clean/repair as necessary.

Using an Ohmmeter, measure the resistance of the Left Front WSS (+) Circuit between the CAB and the sensor.

Is the resistance below 5 ohms?

Yes → Test Complete.

No → Repair the open WSS (+) Circuit.

Perform ABS Verification Test VER-1A.



VER-1A Verification Test

Ignition Off

Disconnect all previously connected Jumper Wires.

Reconnect all previously disconnected connectors.

Reinstall all previously removed Relays.

Ignition On, Engine Not Running

Replace any blown fuses/fuselinks.

With the DRB, reset the module.

With the DRB, monitor the Brake Switch Input while depressing and releasing the brake pedal.

Does the DRB reflect the actual position of the brake pedal?

Yes → Repair is not complete, refer to appropriate symptom.

No → Repair is not complete, refer to symptom BRAKE SWITCH CIRCUIT.

 

[EForbes]

Landry is awesome no matter what thread i see him answer in, its always a total and complete helpful answer, i would go with his tests. Wow great info, i will save myself, and i dont have this problem good luck mireiter.

 

[p-Bar]

ya that'll keep him busy for a while