Pinpoint Test D: Abs False Activation, Abs Too Sensitive, Abs Activates On A Normal Stop

WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

D1 RETRIEVE ABS MODULE DTCs
- Connect the diagnostic tool.
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: ABS Module
- Retrieve and record all ABS module DTCs.
- Are DTCs C1145 or C1155 present?
1. YES : Go to Pinpoint Test C .
2. NO : If DTC C1233 and/or C1234 are present, go to D2.
  For all other ABS module DTCs, go to the ABS Module DTC Chart.
D2 CHECK THE ABS HARNESS AND MODULE FOR WATER INTRUSION
- Key in OFF position.
- Disconnect: ABS Module C135
- Inspect the ABS module connector and module for water intrusion.
- Is there any evidence of water entry?
1. YES : CLEAN the connector and dry it out with low pressure compressed air. INSPECT for evidence of water entry and repair as necessary. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
2. NO : If the active wheel speed sensor tool is available, go to D3.
  If the active wheel speed sensor tool is not available, go to D6.
D3 CHECK THE ABS MODULE OUTPUT USING THE SPECIAL TOOL
- Connect: ABS Module C135
- Disconnect: Suspect Wheel Speed Sensor
- Connect the special tool to the wheel speed sensor connectors.
- Key in ON position.
- Select the correct system polarity on the special tool and turn the special tool power switch to the ON position.
- Is the module output LED illuminated?
1. YES : Go to D5.
2. NO : Go to D4.
D4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN
NOTE: Both circuits must be checked for each DTC.
- Key in OFF position.
- Disconnect: ABS Module C135
- For DTC C1233 , measure the resistance between:
  - ABS module C135-27, circuit 521 (TN/OG), harness side LF wheel speed sensor C150-1, circuit 521 (TN/OG), harness side.
  - ABS module C135-28, circuit 522 (TN/BK), harness side LF wheel speed sensor C150-2, circuit 522 (TN/BK), harness side.
- For DTC C1234 , measure the resistance between:
  - ABS module C135-3, circuit 514 (YE/RD), harness side and RF wheel speed sensor C160-1, circuit 514 (YE/RD), harness side.
  - ABS module C135-4, circuit 516 (YE/BK), harness side and RF wheel speed sensor C160-2, circuit 516 (YE/BK), harness side.
- Are the resistances less than 5 ohms?
1. YES : Go to D7.
2. NO : REPAIR the affected circuit(s). TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
D5 CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE SPECIAL TOOL
- Raise the suspect wheel until it can spin freely. Refer to JACKING AND LIFTING article.
- While monitoring the special tool, slowly spin the suspect wheel.
- Is the current level LED illuminated green and do the sensor output LEDs illuminate and flash?
1. YES : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
2. NO : If the current level LED is illuminated green and the sensor output LEDs do not illuminate or if the current level LED is illuminated red, INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front in this article. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
  If the current level LED is illuminated green and the sensor output LEDs illuminate green but do not flash, INSPECT the wheel speed sensor tone ring and INSTALL new if necessary. REFER to Wheel Speed Sensor Ring - Front in this article. If the tone ring is OK, INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front in this section. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
D6 CHECK THE WHEEL SPEED SENSOR OUTPUT
- Connect: ABS Module C135
- Disconnect: Suspect Wheel Speed Sensor
- For DTC C1233 :
  - connect a fused (5A) jumper wire between LF wheel speed sensor C150-1, circuit 521 (TN/OG), harness side and LF wheel speed sensor C150 pin-1, component side.
  - connect the automotive meter between LF wheel speed sensor C150-2, circuit 522 (TN/BK), harness side and LF wheel speed sensor C150 pin-2, component side.
- For DTC C1234 :
  - connect a fused (5A) jumper wire between RF wheel speed sensor C160-1, circuit 514 (YE/RD), harness side and RF wheel speed sensor C160 pin-1, component side.
  - connect the automotive meter between RF wheel speed sensor C160-2, circuit 516 (YE/BK), harness side and RF wheel speed sensor C160 pin-2, component side.
- Key in ON position.
- Measure the current while slightly rotating the wheel, using incremental turns.
- Does the wheel speed sensor output switch between the low state (4 to 8 mA) and the high state (12 to 16 mA)?
1. YES : Go to D7.
2. NO : INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front this section. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
D7 CHECK FOR CORRECT ABS MODULE OPERATION
- Key in OFF position.
- Disconnect: ABS C135
- Check the connector for:
  - corrosion.
  - pushed-out pins.
  - spread terminals.
- Connect: ABS C135
- Make sure the ABS connector seats correctly.
- Test drive the vehicle above 32 km/h (20 mph), carry out at least one ABS stop and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this article. CALIBRATE the ABS module. FOLLOW the scan tool directions for the calibration procedure. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST DRIVE the vehicle above 32 km/h (20 mph) and CARRY OUT at least one ABS stop.