Welcome,and need help. No overdrive or cruise

Hello,and thanks for the add.
I've got a "new-to-me "1995 Riviera, one owner,with290,000 miles. Regularly serviced.
My problem is that when I first got my baby,the traction, abs,lights were on. Also,my speedometer would stick at 58 mph. But,my cruise worked,and I  had overdrive.
But,after a 400 mile trip, I lost cruise and overdrive. Goes no higher than 3rd gear.
Any ideas?

mrdronenut wrote:

Hello,and thanks for the add.
I've got a "new-to-me "1995 Riviera, one owner,with290,000 miles. Regularly serviced.
My problem is that when I first got my baby,the traction, abs,lights were on. Also,my speedometer would stick at 58 mph. But,my cruise worked,and I  had overdrive.
But,after a 400 mile trip, I lost cruise and overdrive. Goes no higher than 3rd gear.
Any ideas?

It may take a while to get your car straight.

Your transmission should set a code for losing the TCC lockup, such as TCC STUCK OFF I think it's P0740.

If you lose 4th gear (or TCC lockup for that matter) your next stop is a transmission repair shop unless you work on transmissions yourself.

Also see https://rivperformance.editboard.com/t12230-tcc-problems-and-missing-4th-gear

About your ABS and traction lights - can't diagnose this properly from afar, either. Could be a bad wheel sensor. You can check each one with a voltmeter, or someone with a Tech II or later GM diagnostic tool can read the sensor outputs and pinpoint the bad one. Fix requires changing each wheel hub that is found to have a bad sensor, after checking the wiring to determine if that's actually the problem - if you do any highway driving, Do Not Cheap Out on the hubs.

About your speedometer sticking, I have no idea.


Albertj

First, check the simple things.  Inspect the wiring to each wheel sensor at each wheel.  Repair any damaged wires or corroded plugs.  Next, put a jack under each front wheel and jack under the control arm enough to get the tire off the ground.  Try to wiggle the tire side to side, and top to bottom.  If you can feel any play, you need a hub bearing.  When the bearing goes, they usually produce a hum or growl that increases with speed.  When the bearing gets bad enough, it wipes out the sensor, which turns the ABS light and Traction Off lights on.  I also had some corrosion in the harness plug for the rear ABS sensors.  I had to replace the pins and rewire it to fix the ABS light that resulted from that.

I had a transmission problem when my battery went. The resultant low voltage put the transmission into limp home mode. The transmission was stuck in 3rd gear, no OD or lock up. It felt like the transmission was slipping because of the 3rd gear and no lock up. It was stalling the converter much higher. This occurred in the winter on a hard cold start. As soon as the engine warmed up, I could shut the engine down, wait a few seconds and restart, and the transmission was fine. That battery was 11 years old and owed me nothing. I replaced it and everything was fine.

My speedometer also sticks at 58 MPH.  It will stick there as I go faster, then suddenly jump to 70 MPH.  I never really cared that much to even try and diagnose/fix the issue.  I can tell how fast I am going by looking at the tachometer.  1600 = 60 MPH, 2100 = 80 MPH in my 98. Monitoring the speed sensor with my scan tool shows the correct speed even while the speedometer is stuck, so it seems like a mechanical problem in the speedometer head.

LARRY70GS wrote:

My speedometer also sticks at 58 MPH.  It will stick there as I go faster, then suddenly jump to 70 MPH.  I never really cared that much to even try and diagnose/fix the issue.  I can tell how fast I am going by looking at the tachometer.  1600 = 60 MPH, 2100 = 80 MPH in my 98.  Monitoring the speed sensor with my scan tool shows the correct speed even while the speedometer is stuck, so it seems like a mechanical problem in the speedometer head.

Thanks for your help.
After replacing the right front hub,modulator valve, and transmission speed sensor, the general consensus from the repair shops,and scrap yards,the ECM is the next rhing I'm replacing.
After removing the old one, it has "scrap-yard"writing on it.
So,I've ordered a reman with a one year warranty.

mrdronenut wrote:

LARRY70GS wrote:

My speedometer also sticks at 58 MPH.  It will stick there as I go faster, then suddenly jump to 70 MPH.  I never really cared that much to even try and diagnose/fix the issue.  I can tell how fast I am going by looking at the tachometer.  1600 = 60 MPH, 2100 = 80 MPH in my 98.  Monitoring the speed sensor with my scan tool shows the correct speed even while the speedometer is stuck, so it seems like a mechanical problem in the speedometer head.

Thanks for your help.
After replacing the right front hub,modulator valve, and transmission speed sensor, the general consensus from the repair shops,and scrap yards,the ECM is the next rhing I'm replacing.
After removing the old one, it has "scrap-yard"writing on it.
So,I've ordered a reman with a one year warranty.

I think Larry's onto something with the real-time reading off a scan tool - might/should ask your mechanic to connect the scan tool to the car and take it for a ride while logging. The mech will soon be able to tell if it's the ECM (the reading will jump the same) or not (reading will go up and down with RPM and so on).

My guess is you'll end up at:

Southern Speedometer
13625 50th Way N. #6
Clearwater, FL. 33760
727-341-1222

They do repairs and calibrations on mechanical and electronic speedos.

albertj wrote:

mrdronenut wrote:

LARRY70GS wrote:

My speedometer also sticks at 58 MPH.  It will stick there as I go faster, then suddenly jump to 70 MPH.  I never really cared that much to even try and diagnose/fix the issue.  I can tell how fast I am going by looking at the tachometer.  1600 = 60 MPH, 2100 = 80 MPH in my 98.  Monitoring the speed sensor with my scan tool shows the correct speed even while the speedometer is stuck, so it seems like a mechanical problem in the speedometer head.

Thanks for your help.
After replacing the right front hub,modulator valve, and transmission speed sensor, the general consensus from the repair shops,and scrap yards,the ECM is the next rhing I'm replacing.
After removing the old one, it has "scrap-yard"writing on it.
So,I've ordered a reman with a one year warranty.

I think Larry's onto something with the real-time reading off a scan tool - might/should ask your mechanic to connect the scan tool to the car and take it for a ride while logging.  The mech will soon be able to tell if it's the ECM (the reading will jump the same) or not (reading will go up and down with RPM and so on).  




My guess is you'll end up at:

Southern Speedometer
13625  50th Way N.  #6
Clearwater, FL. 33760  
727-341-1222

They do repairs and calibrations on mechanical and electronic speedos.

Another thing that tells me it is the head is that if I smack the lens with my fingers, the needle moves.

LARRY70GS wrote:

albertj wrote:

mrdronenut wrote:

LARRY70GS wrote:

My speedometer also sticks at 58 MPH.  It will stick there as I go faster, then suddenly jump to 70 MPH.  I never really cared that much to even try and diagnose/fix the issue.  I can tell how fast I am going by looking at the tachometer.  1600 = 60 MPH, 2100 = 80 MPH in my 98.  Monitoring the speed sensor with my scan tool shows the correct speed even while the speedometer is stuck, so it seems like a mechanical problem in the speedometer head.

Thanks for your help.
After replacing the right front hub,modulator valve, and transmission speed sensor, the general consensus from the repair shops,and scrap yards,the ECM is the next rhing I'm replacing.
After removing the old one, it has "scrap-yard"writing on it.
So,I've ordered a reman with a one year warranty.

I think Larry's onto something with the real-time reading off a scan tool - might/should ask your mechanic to connect the scan tool to the car and take it for a ride while logging.  The mech will soon be able to tell if it's the ECM (the reading will jump the same) or not (reading will go up and down with RPM and so on).  




My guess is you'll end up at:

Southern Speedometer
13625  50th Way N.  #6
Clearwater, FL. 33760  
727-341-1222

They do repairs and calibrations on mechanical and electronic speedos.

Another thing that tells me it is the head is that if I smack the lens with my fingers, the needle moves.

My speedometer is the least of my worries. I've got to get my overdrive and cruise working. The speedometer is not that important. My abs,traction,and check engine light stays on,and after a 400 mile trip to South Carolina, my overdrive and cruise quit. That's my focus right now.

What do you plan to do next?

albertj wrote:

What do you plan to do next?

Remanufactured ECM

mrdronenut wrote:

albertj wrote:

What do you plan to do next?

Remanufactured ECM

Got a reman from FLASHMASTERS in Cincinnati. First one didn't fix it. It had #1 misfiring. Contacted them,they immediately sent a replacement with a return label for the bad one. Highly recommend these people.
I now have overdrive, 4th gear,and passing gear. Also,I've got cruise control back.
Amazing how a bad ecm can drive you crazy,replacing parts,until you've just gotta go to the "brain box"that tells everything what to do.

mrdronenut wrote:

mrdronenut wrote:

albertj wrote:

What do you plan to do next?

Remanufactured ECM

Got a reman from FLASHMASTERS in Cincinnati.  First one didn't fix it. It had #1 misfiring.  Contacted them,they immediately sent a replacement with a return label for the bad one. Highly recommend these people.  
I now have overdrive, 4th gear,and passing gear.  Also,I've got cruise control back.
Amazing how a bad ecm can drive you crazy,replacing parts,until you've just gotta go to the "brain box"that tells everything what to do.

Sounds good.

I don't recall (in ~10+ yrs) anyone else having this problem on a Riv.