Test 11A - Left Front Sensor Signal Missing/Comparison

NOTE: You must perform Test 1-A, before proceeding with this test.

Test 11A: Reparing Left Front Sensor Signal Missing/Compare (Part 1 Of 2):

Test 11A: Repairing LF Sensor Signal Missing/Compare (Part 2 Of 2):

NAME OF CODE:
LF Sensor Signal Missing

When Monitored:
During an ABS stop.

Set Condition:
The Controller Antilock Brakes CAB monitors the wheel speed signals at all times. If, during an ABS stop, the CAB commands any valve solenoid on for an extended length of time, and does not see a corresponding wheel speed change, the trouble code will set.

Possible Causes:
^ Missing tone wheel
^ Sensor head not properly mounted
^ Failed wheel speed sensor
^ Long stops on ice
^ Failed CAB
^ Running the vehicle on a hoist or chassis dyno

NAME OF CODE:
LF Sensor Speed Comparison

When Monitored:
While driving when vehicle speed exceeds 12 mph.

Set Condition:
The CAB monitors the wheel speed signals at all times. If while vehicle speed is below 12 mph a sensor signal is missing, the trouble code will set as soon as the vehicle speed exceeds 12 mph. On hard acceleration, there is a 2-minute delay before the code is set to allow for possible wheel spin.

Possible Causes:
^ Missing tone wheel
^ Sensor head not properly mounted
^ Failed wheel speed sensor
^ Failed CAB
^ Running vehicle on a hoist or chassis dyno

Left Front Wheel Speed Sensor:

Controller-Antilock Brake Connector:

NOTE: When disconnecting or connecting connectors, always check for terminal damage, pushed out pins or miswired.

NOTE: After completion of steps, or completion of test, perform Verification Test VER-1A.Verification Test VER-1A - ABS