1997 GLT Check engine light - Mass Airflow Sensor, runon

james r chandler · Post by **james r chandler** » 28 Feb 2014, 19:03

Mod note - split from old topic per Forum rules

I have a 1997 850 glt that has been having numerous electrical problems that have been driving me crazy. To start with and be brief the most immediate problem is the check engine light comes on and the code reads PO103 which claims the mass air sensor is bad. I first replaced it with a used one till no success then broke down and bought a new one $120. Again to no success. Still get the same code with the Check engine light as well as hard starting. Now what ??
And on top of that I have a blinking yellow arrow which I have attempted to correct by replacing the pnp switch to now success. I've cleared the code and the transmission runs ok for a few miles or minutes then pops back up and seems to stay in 3rd gear. Oh and here is sometimes a code PO745 generic for pressure control solenoid . I'm took it to a transmission shop to verify the codes and they said to first repair the MAS problem and maybe that would clear the transmission code/problem .
Does anyone think the two are related ? What else could be done for the MAS problem ?
I'm afraid this is all going to lead to a computer control issue and I'm not spending $$$$$ on that.
Maybe be time to push her off a cliff. I'm put so much effort into this problem.
Oh I forgot to mention now when I try turning the car off it wont stop when turning the key. I can pull the key out and she still keeps running. I have to disconnect the mas connector then reconnect it for the engine to stop. I think my car is possessed.

Post by **abscate** » 01 Mar 2014, 05:52

Welcome to MVS!

First thing to replace is your ignition switch, electrical part only.

The fact that your car stops when the Mass air flow sensor (commonly abbreviated MAF) is disconnected is telling ...did you use a genuine Bosch

Stage 0 ...cap rotor plugs plug wires are all things that need to be looked at too.

james r chandler · Post by **james r chandler** » 01 Mar 2014, 15:19

Well I replaced the ignition switch earlier but that didn't change anything. Thou I did put in a used ignition switch in an attempt to save money. I also replaced the pnp switch with a used one with no improvement. But as far as the MAF, I also first put in a used one with no Improvement so I bought and installed a new Bosch MAF but once again, no improvement. I Still have the check engine light one,of course I've cleared it with my code reader but it reappears, its also a bit difficult to start. Earlier I did replace all the spark plugs, cap and rotor with new parts .
I fear there are multiple isssues going on here but trying to sort them out. Maybe they are all related ?
As far as the MAF sensor goes since it is new and still triggers a P0103 code what else would cause that to happen ?

Post by **erikv11** » 01 Mar 2014, 22:33

By far the most common cause of a p0103 is vacuum leaks. The rubber vacuum lines are old and crumbly at this point.

The computer (the engine ECU) is rock rock solid don't worry about that part one iota.

Here's what I would do:

(1) Unplug the MAF, and drive it around. It will go into a default mode. If it runs better with the MAF unplugged, then either the new Bosch MAF is bad or the problem is in the MAF connector. DO this first because it is free and easy.

(2) Inspect the vacuum lines for cracks or breaks. Replace any that are bad. This is a bit of a hassle on a turbo car like yours but there is no way around it. The biggers offender for p0103 codes is the elbow on the passenger's side of the intake manifold, tucked in behind the power steering pump. Get a flashlihgt and peer in there, is it intact or broken off?

The other issue with the transmission I do not have a good lead on but it is almost certainly a separate issue. Work on them one at a time and I would start with the p0103.