Lost communication DTCs are common and should self-clear or become aged after a few minutes. If the DTC doesn't clear then, on the simpler side of troubleshooting, make sure the module has power. You could also pull all the electrical connectors and reseat them.

If this doesn't help, then I would take a look at the CAN bus coming from the TCM to see if it is talking. Problem with this is it requires special tools and CAN bus knowledge.

That's all I got.

 

Thank you! Unfortunately I don’t have the tools or knowledge, but every idea still helps!

 

U0101-00-LOST COMMUNICATION WITH TCM

When Monitored and Set Conditions

When Monitored: This diagnostic runs continuously when the following conditions are met:

• The ignition is on for at least five seconds.
• The battery voltage is between 10.0 and 16.0 volts.

Set Conditions:

• The Body Control Module (BCM) does not receive any CAN Bus messages from the Transmission Control Module (TCM) for greater than five seconds.

Default Actions:

• Features concerning the TCM will not update.

Possible Causes

TRANSMISSION CONTROL MODULE (TCM) POWERS AND GROUNDS
TRANSMISSION CONTROL MODULE (TCM)
CAN C BUS (+) CIRCUIT OPEN
CAN C BUS (-) CIRCUIT OPEN



NO RESPONSE FROM TCM (TRANSMISSION CONTROL MODULE) 8–SPEED

Possible Causes


(A190) FUSED B(+) CIRCUIT OPEN OR SHORT
(Z908) GROUND CIRCUIT OPEN
(F1) FUSED IGNITION SWITCH OUTPUT (OFF-RUN-START) CIRCUIT OPEN OR SHORT
(D29) CAN C BUS (+) CIRCUIT OPEN
(D30) CAN C BUS (-) CIRCUIT OPEN
TRANSMISSION CONTROL MODULE (TCM)


STORED LOST COMMUNICATION DTCS

When Monitored and Set Conditions

When Monitored: This diagnostic runs continuously when the following conditions are met:

•The ignition is on for greater than five seconds.
•The battery voltage is between 10.0 and 16.0 volts.
•The Body Control Module (BCM) is configured correctly.


Set Conditions:

•CAN Bus messages are not received for greater than two seconds.

Possible Causes

CAN C BUS CIRCUITS OPEN OR SHORT
CAN IHS BUS CIRCUITS OPEN OR SHORT
DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
BCM NOT CONFIGURED CORRECTLY
POWER OR GROUND FROM THE REPORTING MODULE
MODULE THAT SET THIS DTC
PREVIOUS SERVICE PERFORMED WITHIN THE LAST 100 KEY CYCLES (FUSE/RELAYS REMOVED, WIRING SERVICE, BATTERY DISCONNECT)
LOW BATTERY/JUMP START CONDITION
CHECK FOR RELATED SERVICE BULLETINS

 

I had the same no communication code between TCM and ESM and thought I was having an issue with the CAN bus. Later after my counterpart doing a thorough diagnosis he realized that the problem was being brought by a bad transmission oil pan. The oil pan was changed and the problem is now gone. You can check that one out too.

 

I had the same no communication code between TCM and ESM and thought I was having an issue with the CAN bus. Later after my counterpart doing a thorough diagnosis he realized that the problem was being brought by a bad transmission oil pan. The oil pan was changed and the problem is now gone. You can check that one out too.

Check the transmission oil pan too. We had the same issue and thought the problem was with the modules or electrical and it was not. The change of the oil pan solved the issue .