Hello, I am French, I have just fitted a Haltech Platinum Sport GM on a 1988 camaro... I am starting to develop the mapping, but since then I have lost the overdrive of the th700R4 gearbox, all the gears pass, but no more overdrive...
Is there a connection with the ECU? an option that I will not have validated? Thank you for your help... (sorry I use google translate)

 

It may be that you lost the TCC lockup, not OD. The lockup is ECM controlled, everything else is hydraulics & mechanical in the 700R4 transmission.

Make sure that the Haltec has a proper MPH/KPH signal, and the TPS signal. I know that the GM ECMs use those for TCC control, not sure about the Haltec ECM. But it is a start.

RBob.

 

Thank you, the TPS info works (useful for the map), the MPH/KPH signal info, I don't know how to check it...

 

Is there a PC/laptop program that shows the ECM data? If so, that should show whether the ECM has MPH/KPH (VSS) data.

RBob.

 

I think I have found the conditions for the OD order here, do you confirm?

 

and here the value to put for the taking into account of the speed... It is the info which arrives from the counter the small yellow box??
I find this value small... What do you think?
Thank you for your answers

 

The TCC settings look OK. The VSS PPM may be off a bit, but should give a reading.

RBob.

 

Well I checked, I have the speedometer pulse information, I continue to search...