C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE
For a complete wiring diagram Refer to the Wiring Information.
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When Monitored:
With the ignition on.
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Set Condition:
When the Left Front Wheel Speed Sensor (WSS) Signal is intermittently missing while vehicle speed is above 25 mph (40 km/h) or erratic wheel speed signal during acceleration or sensed wheel speed is different from other wheels.
Possible Causes |
|---|
| LEFT FRONT WSS LOOSE — B8, B9 CIRCUITS/CONNECTOR/TERMINAL DAMAGE |
| LEFT FRONT TONE WHEEL DAMAGE |
| LEFT FRONT WHEEL/ BEARING DAMAGE |
| IMPROPER LEFT FRONT TIRE PRESSURE/MISMATCHED TIRES |
| LEFT FRONT WSS |
| ANTI-LOCK BRAKE MODULE |
1. CHECK FOR DTC C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE
| NOTE: | This DTC must be active for the results of this test to be valid. |
| NOTE: | If DTC C100A Left Front Wheel Speed Sensor Circuit is present it must be repaired before continuing. |
| 1. | Turn the ignition on. |
| 2. | With the scan tool, record and erase DTCs. |
Make sure braking capability is
available before road testing.
CAUTION:
| 3. | Road test the vehicle over 25 mph (40 km/h). |
| NOTE: | Vehicle must be driven above 25 mph (40 km/h) for set conditions to be met. |
| 4. | With the scan tool, read DTCs. |
Does the scan tool display: C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE active?
Yes
- Go To 3
No
-
Go To 2
2. CHECK WHEEL SPEED SENSOR SIGNALS
| 1. | Turn the ignition on. |
| 2. | With the scan tool, monitor and graph ALL the WSS speeds and compare graph while an assistant drives the vehicle. |
| NOTE: | If graph shows periodic dropouts pay close attention to the tone wheel. |
| 3. | Slowly accelerate as straight as possible from a stop to 25 mph (40 km/h). |
Is the Left Front WSS speed showing 0 mph (0 km/h) or not matching other wheels or showing erratic behavior?
Yes
- Go To 3
No
-
Perform the ABS-INTERMITTENT
CONDITION TEST (Refer to 28
- DTC-Based Diagnostics/MODULE, Antilock Brake (ABS)
- Standard Procedure).
3. CHECK FOR IMPROPER LEFT FRONT TIRE PRESSURE/MISMATCHED TIRES
| 1. | Turn the ignition off. |
| 2. | Check and adjust the Left Front Tire pressure. |
| 3. | Check and adjust all other tire pressures. |
| 4. | Inspect for mismatched tires on vehicle. |
Is the Left Front Tire improperly inflated or mismatched tires on vehicle?
Yes
- Repair as necessary.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No
-
Go To 4
4. CHECK LEFT FRONT WSS LOOSENESS, INSPECT B8, B9 CIRCUITS/TERMINALS FOR DAMAGE
| NOTE: | Check all terminals for broken, bent, pushed out, or corroded terminals |
| 1. | Inspect the Anti-Lock Brake Module harness connector, Left Front WSS, and Left Front WSS harness connector |
| 2. | Inspect the Left Front WSS for looseness, excessive corrosion and not properly fastened. |
| 3. | Inspect the (B8) Left Front WSS Signal and (B9) Left Front WSS Supply circuits between the Left Front WSS and Anti-Lock Brake Module for damage. |
Is the Left Front WSS loose or any of the wiring/connectors/terminals damaged?
Yes
- Repair as necessary.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No
-
Go To 5
5. CHECK LEFT FRONT WHEEL SPEED SENSOR FOR DAMAGE
| 1. | Remove the Left Front Wheel Speed Sensor |
| 2. | Inspect the Left Front Wheel Speed Sensor face for damage. |
Is the Left Front Wheel Speed Sensor damaged?
Yes
- Replace sensor and hub assembly.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No
-
Go To 6
6. CHECK LEFT FRONT TONE WHEEL/BEARING FOR DAMAGE
| 1. | Inspect the Left Front Tone Wheel/Bearing for damage, missing teeth, cracks, corrosion or looseness. |
| NOTE: | The Tone Wheel teeth should be perfectly square, not bent, or nicked. |
Is the Left Front Tone Wheel/Bearing damaged?
Yes
- Repair as necessary.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No
-
Go To 7
7. CHECK LEFT FRONT WHEEL BEARING FOR DAMAGE
| 1. | Inspect the Left Front wheel bearing for excessive runout or clearance. |
| NOTE: | Refer to the appropriate service information, if necessary, for procedures or specifications. |
Is the Left Front Wheel Bearing Damaged?
Yes
- Repair as necessary.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No
-
Go To 8
8. LEFT FRONT WHEEL SPEED SENSOR
| 1. | Replace the Left Front Wheel Speed Sensor in accordance with the Service Information. |
| 2. | Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure). |
| 3. | Road test the vehicle over 25 mph (40 km/h). |
| NOTE: | Vehicle must be driven above 25 mph (40 km/h) for set conditions to be met. |
| 4. | With the scan tool, read ABS DTCs. |
Did DTC C1011-LEFT FRONT WHEEL SPEED SENSOR SIGNAL ERRATIC PERFORMANCE reset?
Yes
- Replace the Anti-Lock Brake Module in accordance with the Service Information.
- Perform ABS VERIFICATION TEST (Refer to 28 - DTC-Based Diagnostics/MODULE, Antilock Brake (ABS) - Standard Procedure).
No