I am also having the same problem on my 1995 Millenia S 2.3L SC. I have replaced all vacuum lines, Installed Brass Tee's, Brand New "ABV Vent and Vacuum" solenoids from Tasca parts!/ Intake Gaskets/ Intake Boot.....Rechecked all of my lines many times, made sure all check valves ( green and white ones, and the two vacuum hoses from the vacuum pump with arrows pointing towards the engine are in their correct "Direction of air flow". And I still Keep getting the dreadful P1540 from ****!!
I am stuck! Poor Milly. Please help!
I thought that I would give this thread some CPR! It's just sad that this can not be remedied.
Thanks in advance for ANY insight on this common issue. (P1540 code ALONE issue)
Actual steps that were taken to resolve P1540 that worked for me.
*Two(2) Vacuum Lines that were wrong!
* All solenoids were Ohm'ed out. ( The Vent and Vacuum solenoids were replaced with new awhile back, and the only solenoid that measured really high (~98 ohms - cold) was the CAC - Bypass Solenoid for the Intercoolers. This made the actuator stuck, also because of the vacuum line mix up, they must have gotten stuck. The CAC Actuator was accidently plugged up the main vacuum line from the vacuum pump, and the ABV Vacuum solenoid was plugged into the CAC Actuator, not sure how that happened, BUT I FOUND IT! YES!!!
* Vacuum lines were re-chased with all of the vacuum diagrams, not just one for the year differences, but the actual different versions of the diagrams to help clarify the lines that were very hard to see on the diagrams....
*ANY LOOSENESS in any of the ABV System hoses was fixed. (Mind you every hose was replaced by me awhile back and Brass Tee's were also installed). If the hose were not nice and tightly snugged, they were trimmed and re-installed to make that "TIGHT SEAL"....
* Also checked all check valves. ( The Green and whites ones, and also the two hoses that have the directional check valves "Inside" of the hose those were good after blowing through them.)
*I also sea-foamed the SH*T out of the ABV Valve through the PCV Valve hose, and I put the 75% pf the can through the gas tank with Super Unleaded Shell Fuel.
* I also checked a lot of solenoid and engine sensors for any corrosion inside the connectors and wire pigtail connectors, ,and kind of ever so slightly being very very careful " I Bent some of the pins very gently with a small screw driver so that everything makes better contact (i.e. the temp sensor for Supercharger, that will also report P1540 codes....).
*Also, before starting up the Miller cycle engine, I disconnected the Negative post (-) from the battery for at least 10 minutes, and then stepped on the brake pedal roughly 5-10 times to discharge any remaining stored memory/ logic that may have been up against me in the cars computer (i.e. P1540 - Gremlins!). Then I re-connected the battery post (-) and started her up like normal!
I will update/ edit this post as I remember what else I did to help me fight the P1540 code battle on my: 1995 Millenia 'S" 2.3 model. "She is very very happy now!
No Check Engine light on at all! Even at highway speeds!
- Vacuum Solenoid (Recently replaced with Brand New Mazda O.E.M.) 34.0 Ohms Cold.
- Vent Solenoid (Recently replaced with Brand New Mazda O.E.M.) 33.0 Ohms Cold.
- Solenoid 91.5 Ohms Cold (= BAD/ DEAD unit) (This was also replaced yesterday with a New Mazda O.E.M. one after finding it suspect. The New one measured out at 41.0 Ohms Cold).
- Vacuum Solenoid 32.1 Ohms Cold.
- Vent Solenoid 35.3 Ohms Cold.
- Solenoid 31.6 Ohms Cold.
Air Bypass Solenoid #1
(Left hand side) 31.7 Ohms Cold.
Air Bypass Solenoid #2
(Right hand side) 31.6 Ohms Cold.
Sensor - Solenoid 38.3 Ohms Cold.
- Solenoid (for: Fuel Pressure Regulator) 37.8 Ohms Cold.