tach signal

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=131507
Printed Date: May 19, 2024 at 1:47 AM

Topic: tach signal

Posted By: dsorensen11
Subject: tach signal
Date Posted: May 30, 2012 at 11:45 AM

I installed an Astrostart RSS2524 into a 2000 camry 4 cylinder. Everything works fine but the tach sense fails and I have to have the starter programed for 1cyl/800rpm. When I do this it starts fine, runs, shuts down at 3000rpm just like it should. I took the tach signal from the injector on the passenger side of the car. Just curious as to why tach sense fails and it needs to be set up as 1cyl. Is this normal?

Replies:

Posted By: racerjames76
Date Posted: May 30, 2012 at 2:07 PM

If I am reading correctly you have the tach wire hooked up to one cylinder's injector...The answer is in that statement I believe. Unless I read your question wrong.

Posted By: dsorensen11
Date Posted: May 30, 2012 at 5:39 PM

So if I pick up the tach signal from one of the injectors, the tach learn function will fail?

Posted By: racerjames76
Date Posted: May 31, 2012 at 9:08 AM

Not sure if I am following correctly. Let me step back and ask some questions to make sure I offer the correct answer.

When set to 1cyl mode, does the tach learn and work correctly?

If you are using standard tach mode, which is usually 6cyl/8cyl on most remote starters that have these program options, then hooking that 6/8cyl input to a 1cyl wire will never learn correctly. Its missing 5-7 more pulses. It thinks only one cylinder out of 6/8 is actually running which is obviously not enough to run a 6/8cyl engine. Therefore it will not accept this as a valid input.

Again if I read correctly you had it hooked to a 4cyl engine on ONE cylinder's injector wire meaning ONE cylinder's injector pulses are being monitored, meaning the remote start must be set to ONE cylinder in order to understand why the pulses are spaced farther apart. It can then interpolate this speed as one of 4 cylinders internally, and comprehend that the engine is indeed running even though it only sees ONE cylinders pulses.

I hope I have understood your situation correctly, and helped you understand. posted_image

Posted By: racerjames76
Date Posted: May 31, 2012 at 9:30 AM

Oh my info says there is a black wire, and a yellow/red at the coils on the left side of the engine that give you a 2cyl pulse each. You can find a 4cyl pulse at the ECM behind the passenger glovebox and that is a BLACK/ orange wire. Sometimes there is also a black wire on the OBDII plug that gives you 4cyl output as well. It will be located on the end of the connector all by itself if present.

Posted By: dsorensen11
Date Posted: May 31, 2012 at 11:34 AM

Thanks Racer. To clarify, I can't get tach learn to work properly at all. R/S works fine when I manually program for 1cyl. According to your explanation, that is what I should expect when going to a single injector. So I guess I can move my tach wire to the ECM to get a 4cyl pulse or leave it as is and program for 1cyl. I'll probably just leave it as it is. Thanks for the help.