Speed Control

U0401-IMPLAUSIBLE DATA RECEIVED FROM ECM/PCM

For a complete wiring diagram consult Diagrams/Electrical.


- When Monitored:
Continuously monitored with the engine running and the ACC Module in normal mode.

- Set Condition:
The ACC Module receives an implausible (default/error value or toggle error or parity error are present) message from the ECM/PCM for 600 millisecond. The ACC module will disable the Adaptive Cruise Control (ACC) system and the ACC UNAVAILABLE message will display in the CCN. Once the DTC goes to stored, the ACC system will return to normal operation. The DTC will be cleared after the ACC Module sees 100 consecutive key cycles of the STORED DTC.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.


Diagnostic Test


1. ACTIVE DTC
NOTE: Diagnose all CAN B and C communication failures before continuing.

Ignition on, engine not running.
With a scan tool, read ACC DTCs.
Is the DTC active at this time?

Yes


- Go To 2


No


- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors, pay particulate attention the CAN circuits.
- Perform the ACC MODULE VERIFICATION TEST. Adaptive Cruise Control (ACC) Verification Test




2. ECM/PCM ACTIVE ON THE CAN C BUS
With the scan tool, select ECU View.
Verify that the ECM/PCM active on the bus.
Is the ECM/PCM active on the bus?

Yes


- Go To 3


No


- (Refer to Communications Test for this DTC and/or Manufacturer Code Charts) for No Response diagnostic procedures.




3. DTCS STORED OR ACTIVE IN THE ECM/PCM
Are any DTCs active or stored in the PCM Module?

Yes


- Diagnose and repair the DTC(s).


No


- Go to 4




4. ACTIVE DTCS IN THE FCM
With the scan tool, select ECU View and select FCM.
With the scan tool, read active DTCs.
Are any Communication DTCs active in the FCM relating to the PCM?

Yes


- (Refer to Communications Test for this DTC and/or Manufacturer Code Charts) for the diagnostic procedures.


No


- Replace and program the ACC Module.
- Perform the ACC MODULE VERIFICATION TEST. Adaptive Cruise Control (ACC) Verification Test