Pinpoint Test G: DTC U0401:00, U0401:67 Or U0401:81

Speed Control

Pinpoint Tests

Pinpoint Test G: DTC U0401:00, U0401:67 Or U0401:81

Refer to Wiring Diagram Set 31, Speed Control for schematic and connector information. Diagrams By Number

NOTE: The speed control sensor is also known as the forward looking sensor.

Normal Operation

The adaptive cruise control system is enabled when the vehicle speed is set and the speed control sensor, which is a radar unit, determines the distance and relative speed of the vehicle that is in the path of travel. The Cruise-Control Module (C-CM) communicates with the PCM over the High Speed Controller Area Network (HS-CAN). The PCM determines if adaptive cruise control system is activated, is in standby mode, is off, is cancelled or a fault in the system has occurred.

- DTC U0401:00 (Invalid Serial Data Received From the ECM/PCM A: No Sub Type Information) - sets when the C-CM receives invalid data from PCM.
- DTC U0401:67 (Invalid Serial Data Received From the ECM/PCM A: A Signal Incorrect After Event) - sets when the C-CM receives invalid data from PCM after a speed control event has occurred.
- DTC U0401:81 (Invalid Serial Data Received From the ECM/PCM A: Invalid Serial Data Received) - sets when the C-CM receives invalid serial data from PCM

This pinpoint test is intended to diagnose the following:

- PCM
- C-CM



PINPOINT TEST G: DTC U0401:00, U0401:67 OR U0401:81

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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G1 CLEAR THE DTCs AND THE RETEST ADAPTIVE CRUISE CONTROL SYSTEM


- Clear the DTCs.
- Test drive the vehicle and activate the adaptive cruise control system.
- Check the C-CM DTCs from the continuous and on-demand self-test.
- Is DTC U0401:00, U0401:67 or U0401:81 recorded?

Yes
GO to G2.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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G2 CHECK THE C-CM AND PCM SOFTWARE LEVEL


NOTE: If the module software is already at the latest level, the IDS will not give the option to reprogram the module software.

- Reprogram the C-CM and the PCM to the latest software level.
- Check the C-CM DTCs from the continuous and on-demand self-tests.
- Is DTC U0401:00, U0401:67 or U0401:81 recorded?

Yes
INSTALL a new PCM. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a incompatible software version.

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