1988 Trofeo gear switch problem and dashboard

[roland]

My 1988 Trofeo make me sick. No backshift to lower gears with kickdown and no power in reason of lost 1-2 gears when it is warm. All gears are working with manually shifting! Its a pretty survivor with only 35000 miles odo. But it shows the trouble code E027 current and history. No further codes with ECM or BCM. I tried to repair the problem with help of the the original manual. E027 tells malfunction of 1 and 2 gear shift and some ways to fix it. I checked the terminals and wireing and replaced the electric switches of 1-2 gear and tcc. Two times I opened the side cover and two days of work are gone without any changes. Oil has correct level.

Since last work at it the digital dash is black LH now. It shows no temp, volt or odometer gauges/datas.

Should I order a new ECM ??? Any other ideas ???

[1977 Cutly]

All gears are working with manually shifting!

Since last work at it the digital dash is black LH now. It shows no temp, volt or odometer gauges/datas.

Should I order a new ECM ??? Any other ideas ???

I will ask my friend (a retired GM mechanic) if he has any ideas. Have you checked continuity with a continuity tester to make sure the wiring harness isn't defective?

[roland]

I will ask my friend (a retired GM mechanic) if he has any ideas.

Many thanks...

Have you checked continuity with a continuity tester to make sure the wiring harness isn't defective?

Yes sir, I ve done. Every terminal and wire to and from tranny, ECM and dash.

[1977 Cutly]

replaced the electric switches of 1-2 gear and tcc.
Since last work at it the digital dash is black LH now. It shows no temp, volt or odometer gauges/datas.

You should check again the grounds, and fix the dash first. I think the two problems are connected. If you get the dash working and the trans is still a problem then deal with the trans next.

My retired friend says the 'trans range switch' is the first place he would investigate.

[roland]

Changed the old ECM with a new one from rockauto. Also a defective ignition coil was a reason of harsh gear shifting. The trofeo runs again without any new or old ECM code. Seems I fixed it...

[1977 Cutly]

Outstanding!
Thank you for keeping us updated.

How about some pictures of your car?