Operation CHARM: Car repair manuals for everyone.

Tech 1 & VIM - ECM Programming

File in Section: 6E - Engine Fuel & Emission

Bulletin No.: 53-65-04

Date: September, 1995

INFORMATION

Subject:
Reprogramming Vehicles Using a Tech 1 and Vehicle Interface Module (VIM)

Models:
1995-96 Passenger Cars and Trucks
OBD II Vehicles with Tech 1 Reprogramming Capabilities

A condition has been detected in the Vehicle Interface Module (VIM) used with the Tech 1. The condition occurs only when using the Tech 1 to reprogram OBD II vehicles.

During a reprogramming event on OBD II vehicles, the Tech 1 will not complete the transfer of the new calibration to the Electronic Control Module (ECM). The fault is not with the Tech 1 but with the VIM. The inability to complete the transfer leaves the ECM "dead" with no calibration, requiring replacement of the ECM.

Although the condition could happen with any OBD II vehicle, it has only been identified on the 1995-1/2 J car. Technicians trying to reprogram a 1995-1/2 J car will receive a message stating "Remote Programming not supported for entered VIN". This message is received after the technician has pulled the information from the vehicle and connects the Tech 1 to the Techline terminal.

The September Techline CD-ROM contains a Tech 1 Mass Storage Cartridge (MSC) update that corrects this condition. The MSC should be updated as soon as possible to avoid any further concerns with reprogramming OBD II vehicles related to the VIM.

If you are not familiar with updating your MSC, please review the introduction section of your MSC user's guide or the terminal Menu Section of the Techline user's guide.

Programming of OBD II vehicles can also be done using the Direct programming method. A T-60, T-50, and T-20 Plus are capable of programming OBD II vehicles using the Direct programming method.