Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations SDETERS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

spoofing a Toyota VSS output 1

Status
Not open for further replies.

thruthefence

Aerospace
May 11, 2005
733
Does anyone know what the 4AGE ECU sees from the vehicle speed sensor? I have been told the sensor is a simple reed switch. I am installing a Toyota engine in another vehicle, and the recipient transmission/speedo drive is mechanical.
thanks in advance, steve
 
Replies continue below

Recommended for you

Your local speedometer shop can probably answer your question, and provide a switch that will bolt right on.



Mike Halloran
Pembroke Pines, FL, USA
 
Toyota has for decades used reed switches in the speedometer and a second one on the transmission (for redundancy).

Without knowing the vintage of the vehicle, no way to answer for certain. At some point they switched over to Hall effect sensors... guessing mostly likely with OBDII in late '96/97.

If you see three wires going to the speed sensor, you can assume it is a Hall effect sensor.. On the speedometer if there is no mechanical speedometer cable drive, it is definitely is not a reed switch.

If two wires, probably a reed switch.. The reed switches can be easily identified by connecting an ohm meter to the two wires and rotating the transmission output shaft or speedometer shaft (if there is one).. You will see it pulse open and closed.

You really need the factory wiring manuals to doing this kind of transplant..

Or you might try posting your question here in the appropriate vehicle forum ..
 
Thanks, guys, the donor is a Toyota AE101 corolla, never sold in an English language country, thus no manual. I have a Corolla book of approximately the same year, and is 'close' but not perfect. You have however verified my 'anecdotal evidence'- the ecu has only one pin for the VSS, and I assume a reed switch in series.
 
This appears to be an older application. So, a VSS combined with a GM DRAC module would give a square wave output that should work. has some info and sells different speed sensors including one that will go inline with a Toyota speedo cable.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor