Simple output when engine is running?
Thread Starter
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
Simple output when engine is running? I'm swapping a car that uses a push button start. The car's original ECM would send a signal once the engine was running to shut off the starter.
Now, the starter runs continuously, so I'm having to manually shut it off.
I've tried a handful of things with the stock truck PCM to output something when the engine is up and running to shut off the starter, but so far nothing reliable.
Before I order an RPM switch or program an arduino to read the tach output, is there something more simple that can be done to trigger a ground once the engine is running, or above a certain rpm?
Now, the starter runs continuously, so I'm having to manually shut it off.
I've tried a handful of things with the stock truck PCM to output something when the engine is up and running to shut off the starter, but so far nothing reliable.
Before I order an RPM switch or program an arduino to read the tach output, is there something more simple that can be done to trigger a ground once the engine is running, or above a certain rpm?
Launching!
Joined: Jul 2010
Posts: 243
Likes: 83
No answers but curious.
I did a swap in a G37 with a push button start but couldn't figure out how to get it to trigger. I used a second button to a relay to actually trigger the starter. The stock button still powers the car and the Holley.
I did a swap in a G37 with a push button start but couldn't figure out how to get it to trigger. I used a second button to a relay to actually trigger the starter. The stock button still powers the car and the Holley.
Thread Starter
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
The original ECU in the car would send a ground to the signal wire on the starter relay to turn it off. That's all I need is a ground.
An RPM switch can be had less than $100, but getting one that allows low RPM activation usually means sourcing custom made ones.
I could have an arduino trigger it from the TAC signal for about $4 and 30 minutes of programming, but was hoping for something a little more clean using the existing hardware/software.
I don't think the truck PCM has a working shift light output and I'm not sure what other unused pins could be repurposed with HPTuners.
Nothing obvious jumps out, that's why I was asking if anyone here had figured out some trickery to make something work.
An RPM switch can be had less than $100, but getting one that allows low RPM activation usually means sourcing custom made ones.
I could have an arduino trigger it from the TAC signal for about $4 and 30 minutes of programming, but was hoping for something a little more clean using the existing hardware/software.
I don't think the truck PCM has a working shift light output and I'm not sure what other unused pins could be repurposed with HPTuners.
Nothing obvious jumps out, that's why I was asking if anyone here had figured out some trickery to make something work.
Thread Starter
TECH Fanatic
Joined: Dec 2019
Posts: 1,129
Likes: 478
I ended up programming a $5 Arduino Nano knockoff to read the Tach output wire and control a relay.
Using an arduino gives me the added benefit of it being capable of a lot of other things down the road.
Using an arduino gives me the added benefit of it being capable of a lot of other things down the road.
