05’ Special Value- No speedo. or Odm.

Installed two speed sensors also a reprogramed eco and still no speedo..?!…

also getting SES light + code speed sensor fault.

ECM not ECO……!!..

Code PO502 Vehicle Speed Sensor “A” Circuit Low.

Your odometer mileage is not showing?
if this is the case, I would believe your cluster has failed.

there have been a few cases of the plastic gear in the transmission breaking, but I believe the odometer would still illuminate.

The speedometer needle does not move the odometer is illuminated but does not change the mileage.. Both have been that way for over a year…. Even when the car was running well.

Two possibilities are:
1) Bad ground for the VSS circuit on either the body or engine, provided the wiring is in good shape.
2) The plastic gear that the VSS mates to in the transmission is either broken, or the internal gear is slipping on the metal shaft because the press fit has become loose.

Which of the 3 wires coming from the harness is the ground?

Attachment 12312

green wire to ECU

Attachment 12313
red wire power

Attachment 12314

black wire ground

You don’t happen to have three clearer pictures of those wiring schematics? I can’t really make them out.

:-)

they’re here in the search engine. You just need the right words. :cool:

https://www.aveoforum.com/forum/f94/2005-aveo-power-ground-distribution-diagrams-15640/


https://www.aveoforum.com/forum/f94/...41/index2.html

Yeah I started playing around with that in Google.

So I have 12 V going to the sensor and the ground is good between the connector and the chassis and the connector and the engine.

I wanted to check continuity with the ECM wire but I didn’t get a chance to unplug the connector from it. . Not sure which of the two ECM plugs would have the dark green wire going to the speed sensor?

also I can’t find any diagrams that show exactly how the speed sensor male end plugs into the transmission. When I removed the sensor itself I saw that white plastic threaded male end sticking out with a square fitting in the middle which is obviously the drive to turn the speed sensor rod. But I’d like to know if I can take that male end out of the transmission casing and inspect it..

At this point a picture of what you are describing would be great as far as the sensor plug goes….

I see now. I’m going to pull out the assembly and check the gear

Attachment 12315

If the gear looks good, see if you can spin in with you finger. If it rotates, the press fit is loose. I don’t believe it can be repaired without disassembly of the tranny.

Well even though the check engine light is on,,, because this is a five speed manual if I leave it I alone don’t think it will have any negative impact on the performance/drivability of the car

I believe you are right so long as your state does not plug your car in for a state inspection
as it would fail.

Michigan used to do that but that’s all a scam it’s just a government money grab