If continuity exists between pins 9 and 69, then refer to steps in eSI for O Engine Crank and/or No Communications Test for continuity between pins 9 and 69 at the TCM. Disconnect the TCM electrical connector and remove TCM from the vehicle.ģ. Take the following steps to check for damaged ground wire bonds if the symptoms for concern are No Engine Crank and/or No Communications with Tech II.Ģ. Electrical grounding of devices such as arc welders, battery chargers, and electrostatic painters, or jumper cables to the TCM heatsink. Physical contact between heatsink and vehicle chassis or other ground circuit points.Ĥ. Positive battery power chassis harness wire to pin 10 and pin 70 of the TCM to be wired without fuse protection of 10-15 amps.ģ. Battery positive wires to touch the heatsink of the TCM Ģ. To avoid damaging the TCM in this manner, NEVER ALLOW the following:ġ. Disconnect the 80-way connector from the TCM when electrically welding etc. Do not ground welders, battery chargers, electrostatic painters or any other equipment to the heatsink. The TCM is manufactured so that the heatsink of the TCM is isolated from all vehicle electrical systems including vehicle chassis ground. The nodes affected described as wire bonds are wire tied to pins 9 and 69 of the TCM. The field returned TCM's were analyzed and found to have two battery ground nodes inside the TCM damaged by excessive electrical current passing through the heatsink of the TCM.
Technicians may find no communication with the TCM and or DTC U0101 stored in other modules.Ī few TCM's have been returned from the field for analysis because of the above symptoms. No engine crank and no communication with TCMĮquipped with Allison LCT-1000(RPO-MW7)Automatic TransmissionsĬustomer may comment that the vehicle will not crank or start/will not shift after the vehicle has been jump-started due to the battery run down or after installation of aftermarket equipment.
What does this mean? |U0101 CHEVROLET code tech notes