Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) CHECK FOR A DTC C1046-LEFT FRONT WHEEL PRESSURE PHASE MONITORING
NOTE: This DTC must be active for the results of this test to be valid.

Turn the ignition on.

With the scan tool, read DTCs.

Record DTC and Freeze Frame information.

With the scan tool, erase DTCs.

Cycle the ignition switch off then on.

CAUTION: Ensure brake capability is available before road testing.

Have an assistant test drive the vehicle in a straight line to 40 Km/h (25 mph) while monitoring all the WSS speeds with the scan tool.

Did the LF WSS speed differ by 8 Km/h (5 mph) or show NO speed?

Yes
1. Go To step 2).
No
1. Refer ABS-INTERMITTENT CONDITION .
2. Perform ABS VERIFICATION TEST - VER 1 .
2) CHECK THE TERMINALS/CONNECTORS/WIRING HARNESS/TONE WHEEL FOR DAMAGE
NOTE: Check all related wiring for bruised, chafed, pierced, or partially broken wires.

NOTE: Check all related connectors for broken, bent, pushed out, or corroded terminals.

NOTE: Check the tone wheel teeth for missing teeth, cracks, or looseness. Teeth should be perfectly square, not bent, or nicked.

Turn the ignition off.

Visually inspect the Anti-Lock Brake Module harness connector, Left Front WSS, Left Front WSS harness connector, and Left Front WSS tone wheel (if applicable) for damage.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform ABS VERIFICATION TEST - VER 1 .
No
1. Go To step 3).
3) CHECK THE VOLTAGE BETWEEN (B9) LEFT FRONT WSS SUPPLY CIRCUIT AND THE (B8) LEFT FRONT WSS SIGNAL CIRCUIT

Fig 1: Checking Left Front WSS Signal Circuit & Supply Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Left Front WSS harness connector.

Turn the ignition on.

Measure the voltage between the (B9) Left Front WSS Supply and (B8) Left Front WSS Signal circuits at the Left Front WSS harness connector.

Is the voltage above 10 volts?

Yes
1. Go To step 4).
No
1. Refer to C100A-LEFT FRONT WHEEL SPEED SENSOR CIRCUIT for the diagnostic repair procedure.
2. Perform ABS VERIFICATION TEST - VER 1 .
4) CHECK THE (B8) LEFT FRONT WSS SIGNAL VOLTAGE AT THE LEFT FRONT WSS HARNESS CONNECTOR

Fig 2: Checking Left Front WSS Signal Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Reconnect all connectors.

Turn the ignition on.

While back probing, measure the voltage between the (B8) Left Front WSS Signal circuit at the Left Front WSS harness connector and chassis ground.

Slowly rotate the wheel by hand.

Did the (B8) Left Front WSS Signal circuit voltage toggle between approximately 1.6 to.8 volts?

Yes
1. Go To step 5).
No
1. Replace the Left Front WSS in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST - VER 1 .
5) CHECK THE (B8) LEFT FRONT WSS SIGNAL VOLTAGE AT THE ANTI-LOCK BRAKE MODULE HARNESS CONNECTOR

Fig 3: Checking Left Front WSS Signal Voltage
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Turn the ignition on.

While back probing, measure the voltage between the (B8) Left Front WSS Signal circuit at the Anti-Lock Brake Module harness connector and chassis ground.

Slowly rotate the wheel by hand.

Did the (B8) Left Front WSS Signal circuit voltage toggle between approximately 1.6 to.8 volts?

Yes
1. Replace the Anti-Lock Brake Module in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST - VER 1 .
No
1. Repair the (B8) Left Front WSS Signal circuit for an open.
2. Perform ABS VERIFICATION TEST - VER 1 .