Code 24 - Speedo staying at 0 (Page 1/1)
842m4SE JUL 01, 02:16 PM
On my '84 4 speed the speedometer is staying at 0 and after a bit of driving the check engine light comes on with a code 24. I've heard the vss and gear can be an issue but I'm not sure in this case. What should I check for?

Another note, when I turn it off the speedo slowly rises from 0 to 7 mph. Not sure if its related but

[This message has been edited by 842m4SE (edited 07-01-2021).]

Mike in Sydney JUL 01, 08:31 PM
Since Code 24 (Vehicle Speed Sensor) - Indicates a problem with the VSS (ECM does not receive any speed pulses while driving, it sounds like a faulty speed sensor or wiring. Have you checked the plug on the speed sensor? Check for a frayed or broken wire from the speed sensor.
842m4SE JUL 02, 02:03 AM

quote
Originally posted by Mike in Sydney:

Since Code 24 (Vehicle Speed Sensor) - Indicates a problem with the VSS (ECM does not receive any speed pulses while driving, it sounds like a faulty speed sensor or wiring. Have you checked the plug on the speed sensor? Check for a frayed or broken wire from the speed sensor.



Yep, the plug looks to be all good. Unplugged and plugged it back in and the speedo was still at 0, all looks to be good there.
TM_Fiero JUL 02, 07:07 AM
You can check the sensor by pulling it out of the transmission and use a multimeter set to A/C, spin the end the gear is on. If the sensor is good, it should read a small amount of voltage. If it reads zero while spinning, the sensor is bad. Be careful when pulling the VSS out not to drop the plastic gear into the transmission. Pulling out the VSS will also let you know for sure if the plastic gear is still good and attached to the VSS shaft. This is a good place to start as it's very easy to remove the VSS.