Antilock Brakes / Traction Control Systems
Anti-Lock Control
Pinpoint Test K: DTC U0100
Normal Operation
- DTC U0100 (Lost Communication With ECM/PCM)- this DTC sets in continuous memory if the brake pedal position switch, and traction control messages that should be received from the ECM/PCM are missing for 5 seconds or longer.
This pinpoint test is intended to diagnose the following:
- PCM
- ABS module
PINPOINT TEST K : DTC U0100
K1 VERIFY THE SCAN TOOL COMMUNICATES WITH THE PCM
- Connect the scan tool.
- Check that a vehicle session can be established using the scan tool.
Can a vehicle session be established?
Yes
GO to K2.
No
REFER to Information Bus to diagnose no communication with the PCM.
K2 CHECK THE ABS MODULE CONTINUOUS MEMORY DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
- Clear the DTCs.
- Wait 10 seconds.
- Repeat the ABS module self-test.
Is DTC U0100 retrieved again?
Yes
GO to K3.
No
The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.
K3 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST
- Check for recorded DTCs from the PCM Key ON Engine OFF (KOEO) self-test.
Is DTC P0562 or P0563 recorded?
Yes
For PCM DTCs, REFER to Computers and Control Systems.
No
GO to K4.
K4 RETRIEVE THE RECORDED DTCs FROM THE ABS MODULE SELF-TEST
- Check for recorded DTCs from the ABS module self-test.
Is DTC B1676 recorded?
Yes
GO to Pinpoint Test A. Pinpoint Test A: DTC B1676
No
GO to K5.
K5 CHECK FOR DTC U0100 SET IN OTHER MODULES
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- All CMDTCs (Continuous Memory Diagnostic Trouble Codes).
- Retrieve the continuous memory DTCs from all modules.
Is DTC U0100:00 or U0100 set in more than 1 module?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.