legacycentral bbs

Not yet. Im curious as to what the click sound is. Its like clock work, start the car, runs fine, makes click sound, rpms drop, check engine light comes on, problem ensues.

Glad I was able to fix the problem for like a week lol

It's probably the solenoid successfully clicking over to measure atmospheric pressure and failing. I bet you've got a vacuum line leaking or hooked up wrong.

Or it could be the other way around....the solenoid could be switching over to read boost/vacuum and failing. If you've checked the pressure exchange solenoid and it appears to be working fine and the wiring is fine, that leaves the MAP sensor or MAP sensor wiring.

I agree with Josh.

The only reason I say it clicks over to read atmospheric pressure is because the default state of the solenoid is to measure the engine boost/vacuum, and atmospheric pressure checks are few and far between.

Regardless, the reason it is throwing a code is because it is reading the same pressure when it compares the two readings. That is how the ECU decides if there is a problem with the system. Given that, either the MAP sensor or MAP wiring is broken, or the vacuum lines are hooked up incorrectly or broken.

I replaced all the vacuum lines this weekend but i'll go and double check. I was able to fine a used MAP sensor (tested for correct operation) in europe that is only costing me $50 bucks. Hopefully that will be the end of things once I get it installed.

Still waiting on the new pressure sensor to be delivered but i have been thinking, besides the pressure solenoid, pressure sensor, wiring for both or vac leak, is there anything else that would cause the ecu to throw code '45'?

Not that I'm aware of.

Replaced the pressure sensor. Didn't solve the issue. I am at a complete loss with this right now.

One thing that I haven't addressed is the connection between the pressure solenoid and the starter relay. Should I consider that to be an option?

Bryan,

Ok, so let's run through everything you've done. I know I can probably piece these answers together, but would like to recap everything. Please quote my message or copy & paste it in your reply and answer each line.

- Have you replaced or verified both the pressure sensor and pressure exchange solenoid?

- Have you checked for 12v at the pressure exchange solenoid when the ignition key is on?

- Have you checked the resistance of every single wire from the ECU to both the pressure exchange solenoid and pressure sensor? The pressure exchange solenoid will have one wire, while the pressure sensor will have three wires. The resistance between the ECU connector and the connectors in the engine bay should be close to 0 ohms.


If you've done all those things and they all check out, really the only thing left is the ECU. If you can find a used ECU or someone in your area where you could test their ECU in your car, that would help you rule out or identify the ECU as the problem.

Bryan,

Ok, so let's run through everything you've done. I know I can probably piece these answers together, but would like to recap everything. Please quote my message or copy & paste it in your reply and answer each line.

- Have you replaced or verified both the pressure sensor and pressure exchange solenoid?

Yes I have replaced both of them

- Have you checked for 12v at the pressure exchange solenoid when the ignition key is on?

Yes, measured at 11.7V (which is within spec)

- Have you checked the resistance of every single wire from the ECU to both the pressure exchange solenoid and pressure sensor? The pressure exchange solenoid will have one wire, while the pressure sensor will have three wires. The resistance between the ECU connector and the connectors in the engine bay should be close to 0 ohms.


Yes, I have done this, all resistances were ~0 ohms (I am going to recheck all of them this weekend though just to verify)

If you've done all those things and they all check out, really the only thing left is the ECU. If you can find a used ECU or someone in your area where you could test their ECU in your car, that would help you rule out or identify the ECU as the problem.

This is what I was leaning towards. After I checked the power and resistance of both connectors, replaced the pressure solenoid and the vacuum line between the solenoid and the pressure sensor, the problem was solved for roughly a week. Then it came back one morning when I started the car. After that I replaced all vacuum lines and the pressure sensor itself, which did not solve the issue.

I am going to check the wiring one more time this weekend and then if that all checks out looks like a new ECU is in the mix.

Does the solenoid still click with key on in D-Check mode?

Well it sounds like you're on the right track. There may be a loose connection in the ECU somewhere, but finding another ECU is probably going to be the easiest option.

Alphius wrote:Does the solenoid still click with key on in D-Check mode?

Yes it does.

Josh - picking up a new ECU saturday from a local guy for $50. Will report back when I have my next repair update.

Thanks guys for all the help.

Sounds good.

Just wondering if the "new" ecu fixed the problem?

I guess I should have reported back about this. Didn't replace the ECU, I remeasured all values on all of the connector wiring, found that I had a major resistance issue on the MAP sensor wiring (about 17 ohms). Ran new wiring to the ecu and solved the issue.

So I guess never rule out wiring, even if you already have tested it.

Hey! Glad you found the problem! Thanks for reporting back. It's always nice to hear of an issue being resolved and what fixed it so we can all learn from it!