Pinpoint Test I : U0100, U0115, U0294, U0401
- Refer to Module Communications Network
for schematic and connector information.
Normal Operation and Fault Conditions
When a network message is suspected as missing or confirmed by a missing message DTC (U-code), its important to look for other conditions that may also be present in additional modules throughout the vehicle. Once a DTC sets in the TCM, it may be helpful to review the complete message list available in the Master DTC Chart and see what other modules also rely on the same message and run the self-test for those modules. If the message is missing from other modules, the same DTC may also set in those modules. Confirmation of missing messages common to multiple modules may indicate the originating module is the source of the concern or the communication network may be experiencing some problems.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition TCM U0100:00 Lost Communication With ECM/PCM "A": No Sub Type Information Lost communication with the PCM but the TCM is receiving messages from other modules. TCM U0115:00 Lost Communication With ECM/PCM "B": No Sub Type Information Lost communication with the PCM but the TCM is receiving messages from other modules. TCM U0294:00 Lost Communication With Powertrain Control Monitor Module: No Sub Type Information Lost communication with the PCM but the TCM is receiving messages from other modules. TCM U0401:00 Invalid Data Received from ECM/PCM A: No Sub Type Information Receiving CAN messages from the PCM but the PCM is indicating failures of certain key signals. Possible Sources
- Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
- Fuse
- Network
- I1 READ AND RECORD ALL DTCS
- Using the diagnostic scan tool, retrieve all DTCs.
Are DTCs U0100, U0115, U0294 and/or U0401 present?
Yes GO to I2 No The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - I2 CHECK FOR CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (DTCS)
- Using the diagnostic scan tool, retrieve all continuous memory DTCs.
Did DTC P0562 or P0563 set?
Yes For DTC P0562 or P0563, Refer to Engine Controls - Powertrain DTC Charts & Descriptions (Except Diesel & Hybrid) . No GO to I3 - I3 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Carry out the network test.
Does the PCM pass the network test?
Yes GO to I4 No REFER to: Communications Network . - I4 CHECK FOR DIAGNOSTIC TROUBLE CODE (DTC) U0100, U0115, U0294 AND/OR U0401 SET IN OTHER MODULES
- Using the diagnostic scan tool, retrieve all DTCs.
Did DTC U0100, U0115, U0294 and/or U0401 set in other modules?
Yes Refer to PCM Guided Routine Testing . No The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.