Hi,

After searching the forums (yep, I followed the directions for newbies), I didn't find an answer to a question I've got, so here it is.

My mom brought her '99 Infiniti Q45 to an Infiniti dealer b/c her CEL was on. They diagnosed it as throwing error code P1105 - defective MAP Solenoid.

Evidently and not surprisingly, the stealer wants $$$$ to fix it. My question to you, the experts, is how much could she reasonably expect to pay to have it fixed? IME, it's often cheaper to buy the parts online and just pay a repair shop for the labor. Should we go that route?

Thanks for your input!

Support your local economy by paying the neighborhood dealer to fix it.

Welcome to NICO! If it's easy to replace you could always buy one from Infiniti of Scottsdale and put it in yourself. You might also check the connection to the solenoid, just to make sure the terminals aren't corroded. I had that happen once on my old Q's EGR control solenoid.

Heath
Modified by Q451990 at 12:33 AM 1/27/2010

Check http://www.infinitipartsusa.com to see what the part costs at a 25% discouint off suggested list.

Many dealers mark up over suggested list. Compare to your dealer's quote.

Download FSM at http://www.nicoclub.com/FSM/Q45/

From reading through your FSM the MAP/Baro solenoid in the 99Q looks an awful lot like the EGR solenoids in the G50 and should look something like the ones in the pic. On your Q it's located on the backside of the plenum/engine towards the firewall and does look very accessible with minimal labor to replace.

Once you find it, see if one of the 2 nipples might be broken off or one of the hoses that connects to it is split. You can also test the function of the solenoid with a 9v battery and a couple of jumpers. Read through the diagnosis on pages EC-339 to EC-347 but start with the simple stuff (broken nipple/split hose).

http://www.nicoclub.com/FSM/Q45/1999_Q45/1999_Q45/

Don't confuse the old solenoid [air control valves] with MAP SENSOR which was not used on older Q45 [90-96].

Necessary to measure barometric pressure in plenum to comply with OBDII.

The sensor appears to be controled by a solenoid that looks very much like the EGR control solenoid on the early Q. There is a different DTC for the actual sensor.

Looks like we're more interested in this problem than the original poster

Heath