Po780 Code

[gasenvy]

I have 96 lsi 4cylinder automatic an a po780 codeshow up after I use the scan tool. What is it for? What needs to be done to get rid of the code? get as much detail as possible. This could determine fate of my '96.

Thanks,
Gasenvy

[91Caprice9c1]

I'm not finding much detail about DTC P0780 except that it is for a 'shift malfunction.'

Have you noticed strange shift behavior?
a) starting out in second
b) erratic upshift/downshift
c) no 'kickdown' at cruising w/WOT
d) no upshift @ WOT

I came across a post via google search where a 96 metro gave different speeds between a scan tool and that displayed on the dash indicating a problem with the Vehicle Speed Sensor.

Reattach your scan tool and select display data, have a look at the vehicle speed and see that it:
a) matches speedometer readout +/- 3mph
b) is stead and not erratic

-MechanicMatt

[gasenvy]

Thanks,
I'll try that.
Gasenvy

Originally Posted by 91Caprice9c1

I'm not finding much detail about DTC P0780 except that it is for a 'shift malfunction.'

Have you noticed strange shift behavior?
a) starting out in second
b) erratic upshift/downshift
c) no 'kickdown' at cruising w/WOT
d) no upshift @ WOT

I came across a post via google search where a 96 metro gave different speeds between a scan tool and that displayed on the dash indicating a problem with the Vehicle Speed Sensor.

Reattach your scan tool and select display data, have a look at the vehicle speed and see that it:
a) matches speedometer readout +/- 3mph
b) is stead and not erratic

-MechanicMatt