Pinpoint Test J : U0100:00, U0401:00, U0401:81 Or U0401:82

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
HUD U0100:00	Lost Communication With ECM/PCM "A": No Sub Type Information	Sets in continuous memory in the HUD module if data messages received from the PCM through the GWM are missing for 5 seconds or longer.
HUD U0401:00	Invalid Data Received from ECM/PCM A: No Sub Type Information	Sets in continuous memory when the HUD module receives invalid cruise control network data from the PCM through the GWM for 5 seconds or longer.
HUD U0401:81	Invalid Data Received from ECM/PCM A: Invalid Serial Data Received	Sets in continuous memory when the HUD module receives invalid network data for speedometer or EV drive range from the PCM through the GWM for 5 seconds or longer.
HUD U0401:82	Invalid Data Received from ECM/PCM A: Alive/Sequence Counter Incorrect/Not Updated	Sets in continuous memory when the HUD module fails to receive updated cruise control data from the PCM through the GWM.

Possible Sources

Communication concern
GWM concern
PCM
HUD concern

J1 CHECK THE HUD (HEAD UP DISPLAY) MODULE CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)

Ignition ON.

Using a diagnostic scan tool, perform the HUD module self-test.

Clear the Diagnostic Trouble Codes (DTCs).

Wait 10 seconds.

Repeat the HUD module self-test.

Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes	DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). REFER to DTC Chart: HUD Module in this information. Refer to Diagnostic Trouble Code (DTC) Chart

GO to J2

J2 PERFORM THE PCM (POWERTRAIN CONTROL MODULE) KOEO (KEY ON, ENGINE OFF) SELF-TEST
- Using a diagnostic scan tool, perform the PCMKOEO self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). REFER to: Electronic Engine Controls .

No GO to J3

J3 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (CM DTCs).
Are any Diagnostic Trouble Codes (DTCs) set?

Yes REFER to: Communications Network .

No GO to J4

J4 RECHECK THE HUD (HEAD UP DISPLAY) MODULE DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, clear the HUD module Diagnostic Trouble Codes (DTCs).

Ignition OFF.

Ignition ON.

Wait 10 seconds.

Using a diagnostic scan tool, perform the continuous memory self-test.

Check the HUD module Diagnostic Trouble Codes (DTCs).

Is DTC U0100:00, U0401:00, U0401:81 or U0401:82 still present?

Yes

GO to J5

No	The system is operating correctly at this time. The DTC may have set due to high network traffic or an intermittent fault condition.

J5 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.

CHECK the vehicle service history for recent service actions related to the PCM, GWM or HUD module. If recent service history is found:
- verify correct replacement module was installed
  - vehicle parts build may be used to verify correct part fitment
- verify the configuration of replacement module was correct
  - re-configure module using as-built data if prior configuration is suspect
- verify the module was not obtained from a like vehicle and installed into customer vehicle
  - return the swapped module to source vehicle and obtain new replacement module

Operate the system and determine if the observable symptom is still present.

Is the observable symptom still present?

Yes

GO to J6

No	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

J6 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the PCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the PCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM GUIDED ROUTINE TESTING

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.