Solenoid valve resistance different
Solenoid valve resistance different
(OP)
During a retrofit I have a new solenoid valve (automotive 12V)that has a coil resistance value of 12.2 ohms. The solenoid valve is actuated by the ECU. The original solenoid valve for this ECU had a resistance value of 10.3 ohms. It doesn't appear the new valves are funtioning. Installing the earlier valve is not practicle. Is the resistance value difference enough that the ECU can not operate the new valve? Is there a way of making the new higher resistance valve work? Thanks!





RE: Solenoid valve resistance different
What's the application?
Some types of coils rely on a spike of in-rush current to get them to shift. If your current supply is not providing that, this might be a problem.
Other times the coil may be supplied with a reduced voltage or a duty-cycled signal. If the new coil is not designed for that (requires full voltage supply, or isn't designed for fast cycling of a duty-cycled signal), that's going to be an issue.
RE: Solenoid valve resistance different
RE: Solenoid valve resistance different
If it's a duty-cycled application and the solenoid you've put in is not designed for that, it ain't gonna work.
RE: Solenoid valve resistance different
RE: Solenoid valve resistance different
RE: Solenoid valve resistance different
RE: Solenoid valve resistance different
I have done the 996 3.6l motor installation on my track car (with a Motec,) and I'm familiar with the solenoid you describe. It is a simple on-off solenoid, and doesn't require a PWM to operate. However, oab is correct. Many controllers use various techniques to verify the solenoid is actuating, as part of the OBD requirements for the vehicles. I am not familiar with the 997 ECU or any differences from the 996 ECU, which I did study before setting up my Motec. With all of that said, here is what is suspect:
The 997 ECU is monitoring the solenoid via inductive feedback (more than simple resistance.) The ECU is finding the solenoid to be outside it's acceptable limits, so it's not operating the solenoid at all, which is the ECU's "limp-home" mode for that solenoid. If I'm right, you should be able to diagnose this with an OBD reader, as it should be spitting out a code for a failed cam phasing solenoid.
-Tony Staples
www.tscombustion.com