Pinpoint Test K: DTC U0100

Anti-Lock Control - Three-Channel

Pinpoint Test K: DTC U0100

Normal Operation

- DTC U0100 (Lost Communication With ECM/PCM)- this DTC sets in continuous memory and on-demand 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:

- Communication network concern

- PCM

- ABS module

PINPOINT TEST K : DTC U0100

K1 VERIFY THE SCAN TOOL COMMUNICATES WITH THE PCM

- Connect the scan tool.

- Verify 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
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 B1317 or DTC B1318 recorded?

Yes
For DTC B1317, GO to Pinpoint Test A. Pinpoint Test A: DTC B1317

For DTC B1318, GO to Pinpoint Test B. Pinpoint Test B: DTC B1318
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 CMDTCs (Continuous Memory Diagnostic Trouble Codes) from all modules.

Is DTC U0100:87 set in the Remote Function Actuator (RFA) module (if equipped) or DTC U0100:00 in the Restraints Control Module (RCM)?

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.