Jump to content
Sign in to follow this  
Clint Young

Speedometer Not Working

Recommended Posts

Hello - I am looking for some input here. The situation is as follows:

 

The speedometer does not work on my 1993 Toyota Corolla DX 1.8L. It stays at 0Mph until probably 40-50 Mph and then shoots up to about 67 and stays there whether you go 80 or 50. Another strange thing is that the clock hours count 1,2,3,4,5...12. And keep cycling. I was told that the circuit that the clock and the speedo run off of is completely separate, but they both went out at almost the exact same time. (if not, within a day or so).

 

Troubleshooting performed is as follows:

 

Today I removed the speed sensor from the transmission. The gear wheel on it moves as I think it should feel. There is no wear on the gear, nor is there any wear on the gear inside of the transmission. I removed the insturnment cluster today and looked at all the connections. They didn't appear to be dirty, but I used a Q-Tip and some Alcohol and cleaned all the connections. I removed the front cover of the housing and the speedometer moves as it should (I can move it to wherever, and it moves back down at a set pace/resistance.)

 

I am wondering what the problem might be? It sounds like a potential ground somewhere to me, but I cannot be sure since I don't have such detailed wiring diagrams to diagnose this.

 

Has anybody heard of anything similar, or have any recommendations as to what to try next? I really appreciate your input. Thanks!

Share this post


Link to post
Share on other sites
your clock and speedo issue could be seperate. it could be the speedo sensor in the trans, ontop of the unit. its 2 red wires.

 

Is it possible to test the speedo sensor with a multimeter? Found autozone has it, but it is $189. I'd like to have it 100% narrowed down before making the purchase. Thanks for your response.

Share this post


Link to post
Share on other sites

yes, but im not sure of the test procedure. a simple test of the parts resistance (should be more than 0 and less than infinite) could give you a basic idea. i'd suggest pulling one from a junked car with the same engine/trans.

Share this post


Link to post
Share on other sites

You should be able to measure the voltage across the pins on the speed sensor. You can backprobe the sensor (need 12V power to measure the sensor). If you stare at the pins, sensor oriented with bolt hole on top, pins should be numbered 3 -2 -1 from left to right. Pin 1 is source (+12V), Pin 2 is ground, and pin 3 is signal. Probe pins 2 and 3 and measure the voltage as the shaft is rotated - should go from 0V to source voltage four times for every full revolution of the shaft.

Share this post


Link to post
Share on other sites
You should be able to measure the voltage across the pins on the speed sensor. You can backprobe the sensor (need 12V power to measure the sensor). If you stare at the pins, sensor oriented with bolt hole on top, pins should be numbered 3 -2 -1 from left to right. Pin 1 is source (+12V), Pin 2 is ground, and pin 3 is signal. Probe pins 2 and 3 and measure the voltage as the shaft is rotated - should go from 0V to source voltage four times for every full revolution of the shaft.

 

 

Thanks! I'll give that a go here in the next day or so. :)

Share this post


Link to post
Share on other sites
Hello - I am looking for some input here. The situation is as follows:

 

The speedometer does not work on my 1993 Toyota Corolla DX 1.8L. It stays at 0Mph until probably 40-50 Mph and then shoots up to about 67 and stays there whether you go 80 or 50. Another strange thing is that the clock hours count 1,2,3,4,5...12. And keep cycling. I was told that the circuit that the clock and the speedo run off of is completely separate, but they both went out at almost the exact same time. (if not, within a day or so).

 

Troubleshooting performed is as follows:

 

Today I removed the speed sensor from the transmission. The gear wheel on it moves as I think it should feel. There is no wear on the gear, nor is there any wear on the gear inside of the transmission. I removed the insturnment cluster today and looked at all the connections. They didn't appear to be dirty, but I used a Q-Tip and some Alcohol and cleaned all the connections. I removed the front cover of the housing and the speedometer moves as it should (I can move it to wherever, and it moves back down at a set pace/resistance.)

 

I am wondering what the problem might be? It sounds like a potential ground somewhere to me, but I cannot be sure since I don't have such detailed wiring diagrams to diagnose this.

 

Has anybody heard of anything similar, or have any recommendations as to what to try next? I really appreciate your input. Thanks!

 

 

Interesting problem. I don't think speedometer and clock problems are connected.

Speedometer may have to do with sensor, wiring or even your ECM.

The clock is probably just gone bad.

Share this post


Link to post
Share on other sites

Does the 93 gen have an electronic spedo? My 92 had a mechanical sepdo and it quit working. I took off the cable and spun it with a cordless drill to see if it spun... Nope.. So i just followed the spedo cable back untill i found a short section that was broken...

Edited by JeffG

Share this post


Link to post
Share on other sites

Yes, he definitely is correct. Electronic speedometer. Interesting that you would bring this up, because it has been on my mind as well. The odometer/tripometer work just fine, just the speedo does not function. Is it something else that runs the odometer? I am going to try and get a replacement speed sensor to see if that will do it.

Share this post


Link to post
Share on other sites

well i think the VSS (vehicle speed sensor) feeds signal to the speedo and odometer, since theyre in the same unit, but it wouldnt hurt to test the sensor and check the wiring.

Share this post


Link to post
Share on other sites
well i think the VSS (vehicle speed sensor) feeds signal to the speedo and odometer, since theyre in the same unit, but it wouldnt hurt to test the sensor and check the wiring.

I think it uses the same sensor, but splits the signal for the speedometer and the odometer.

Share this post


Link to post
Share on other sites

well i think the VSS (vehicle speed sensor) feeds signal to the speedo and odometer, since theyre in the same unit, but it wouldnt hurt to test the sensor and check the wiring.

I think it uses the same sensor, but splits the signal for the speedometer and the odometer.

i think i hear an echo in here...

Share this post


Link to post
Share on other sites

FIXED!!!

 

Replaced the Speedometer guage cluster and all is well!

 

Went by the junkyard today, and lucky for me, they happened to have 1 Toyota Corolla sitting there. It was a 1993 exactly like mine! :) Stripped the rear taillight electrical harness, rearview mirror, speed sensor, guage cluster, cigarette lighter, strut tower dust covers and a window knob to roll it down. :) Pretty good haul when I was there. Now the only thing I need to make this car complete again is a replacement clock and antenna.

 

Thanks so much for all your help! Much appreciated.

Share this post


Link to post
Share on other sites

hmm, so is your odometer off now?

 

you can roll it to your correct mileage by turning the trip odometer with a small implament

Edited by Bitter

Share this post


Link to post
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

trap


×
×
  • Create New...