ASD Relay Operation
I am checking if it is normal for the ASD Relay to be switched on and then off when the ignition is turned on only? The ASD relay turns on for a few seconds and then it goes off. Is this the normal operation?
Yes, it is normal. Key on the relay does a self check and then turns off. It will turn on again once the PCM sees the engine cranking.
That is a rather common operation on a lot of vehicles. If things are activated to be ready for start and run but no signal from CKP, those things are deactivated. The ones I have seen stay activated initially for just a very short time until CKP shows up.
Hi Erwin, yes I agree that is normal on some Chrysler’s then they changed it on some models and some years and then they brought it back , I will also mention that I almost got burned on checking fused power with key on engine off when I didn’t have power on one end of fuse and other end had 12 volts I definitely thought I had a bad fuse check it and it was good, only to find out you need two…
Totally normal, AND, for helpful testing purposes, you can turn the relay ON with the scan tool. That allows you to test for B+ power at places like injectors and the ignition coil(s).
The Snap-On Solus Pro would quickly cycle the ASD Relay on then back off, repeatedly. I been a bit behind on the current scan tool meta though.
As stated this is normal. On some relays both power and ground side of the relay's control circuit are controlled by the pcm. Add into the mix that the ground side of the control side may or may not show a bias voltage when not activated.
Cool. Just wanted to be sure. This vehicle had a bad ASD relay and the crank sensor 5v ref is shorted to ground through the sensor.
I got a new crank sensor but now the vehicle starts and cut off every time. A used computer was fitted. Do I need to get it programmed first? Is security values below showing a fault? This Jeep is a RHD built in the USA for export. The theft light goes out when ignition is turned on but comes on briefly just before it cranks.