Help! Dealer is misdiagnosing my car!

[ultravorx]

Hey guys, i have my car at the dealer today for a check engine light throwing a code of p0108. Which is a high siganl on the MAP (Manifold Absolute pressure) sensor. The dealer said they are replacing the MAF (MAss air flow) sensor. When i questioned it, the dealer said my car does not have a MAP sensor, the MAF sensor takes its place? Is this right, or is the dealership just being lazy. I always thought the MAP sensor was in the EGR assembly?

If I do have a MAP sensor, can someone give he right part number for it as well so i can bring it to the dealer?
Thanks,
Frank

[MENINBLK]

I always thought the MAP sensor was in the EGR assembly?

I've always seen the MAP Sensor either on the firewall, or mounted NEAR the EGR.
When its mounted near the EGR, it usually shares the vacuum supply.

I don't remember ever seeing one under our hood, but Dennis or Lidio
may know for sure if we do have one.

MAP = Manifold Absolute Pressure.

A high Map Signal usually indicates a vacuum leak or broken vacuum line.
It could also be a clogged exhaust/collapsed cat.

[SergntMac]

As you have been told, there is in fact a MAP sensor reporting data to the EEC on a regular basis. I'm not a mechanic, so I can't tell you exactly what this data indicates, or how it affects the EEC, but it does.

I monitor my OBDII data with a live scanner from www.scangauge.com It give me a lot of 411 on what's going on under the hood, and MAP numbers (expressed in PSI according to the scangauge handbook) is one of the parameters. I've been using it for about a year now, and I note that the MAP PSI mirrors the vacume/boost information I get from my AutoMeter boost gauge. When the boost gauge goes up, so does the MAP, almost with identical numbers, 15 PSI of boost on the gauge, reads 16.4 PSI in MAP numbers from the OBDII. When at idle, the boost gauge reports vacume, and the MAP PSI is down around 4.5 PSI.

I see a relationship in these numbers, but I do not know more about MAP function. While MenInBlk suggests a high number means a leak, I can't say more because I don't know. I've been treating it as an indication of internal manifold pressure, a factory boost gauge so to speak, but I could be treating this data wrong too. If I am leaking something when the MAP PSI goes high, I like the feeling.

I can say you have a MAP sensor, unless of course, what I'm reading from my OBDII port is the magnetic pull of the Sun...

BTW, the only data missing from the OBDII port, is fuel pressure, and that's due to the MM's "returnless" system.

[grampaws]

The MAP MAF and TPS are used to determine engine load

for fuel delivery and engine ignition..they are all on your engine
and important to the efficient operation of the engine...it is
common for ths part to fail and the code should be reliable..
as long as the connections and wire are in good shape..
and no vacuum leaks exist such as a loose vac hose ...
it measures pressures in the intake manifold...
Wide open throttle low Vaccum readings or in your case Boost psi
Idle closed throttle High Vaccum readings

[ultravorx]

I did find out that the MAP sensor is actually part of the whole EGR assembly, so the whole unit needs to be replaced. Looks like the dealer is trying to stiff me!


Frank

[grampaws]

If it is part of the EGR try to have it covered under Emissions Warranty!

EGR is an Emissions component!

[KilledKenny]

P0108 - Barometric Pressure/Manifold Absolute Pressure (BARO/MAP) Sensor High Voltage Detected
This sensor is part of the EGR System Module assembly. Part# 3W7Z 9D475-BA (Note: Part may change to updated number) The ESM is an updated DPFE EGR system. It functions in the same manner as the conventional DPFE system, however the various system components have been integrated into a single component called the ESM. The flange of the valve portion of the ESM bolts directly to the intake manifold with a metal gasket that forms the measuring orifice. This arrangement increases system reliability, response time, and system precision. By relocating the EGR orifice from the exhaust to the intake side of the EGR valve, the downstream pressure signal measures manifold absolute pressure (MAP). The system provides the PCM with a differential DPFE signal, identical to a traditional DPFE system.
They should not be replacing the MAF sensor for this code unless they have other info or trouble codes that they are not tell you. Hope this helps. :)

[grampaws]

p 0102 is the MAF mass air flow circuit
p 0108 is the MAP sensor and it is on the fire wall not the
EGR valve it is separate from the EGR just behind it!
Passenger side. Your instincts seem to be correct!!
I unplugged the sensor on the egr it didnot set a code
the sensor behind it unplugged set the code you are
getting-:)
F8SE - 9c915 -AA was the part number on the firewall
when unplugged set the p0108 code:)

[grampaws]

A DPFE error should set a code p0400 to p0410..then the

sensor on the EGR is suspect...or the EGR itself or the
passages leading to it are plugged but this is not the
code you're getting:)
Part number is of a 2003 marauder

[KilledKenny]

p 0102 is the MAF mass air flow circuit
p 0108 is the MAP sensor and it is on the fire wall not the
EGR valve it is separate from the EGR just behind it!
Passenger side. Your instincts seem to be correct!!
I unplugged the sensor on the egr it didnot set a code
the sensor behind it unplugged set the code you are
getting-:)
F8SE - 9c915 -AA was the part number on the firewall
when unplugged set the p0108 code:)

That is not the map sensor on the firewall. That is the Vapor Management Valve. It is used for the Evap system. The Map sensor is integrated into the EGR valve along with the EGR control solenoid. This EGR system is of a different design than the old DPFE style. This system detects engine vacuum differences while the older style detects exhaust pressure differences. Basically new style takes its readings on the intake side while the older style gets its readings from the exhaust end.

[grampaws]

The information and the code I'm getting tells me it is the MAP sensor .
I will check further but I have to go with the information I have..
The dpfe monitors the operation of the EGR and uses manifold pressure to
do so..I am pretty sure it is not the map sensor ..If you are correct then
I should not be getting the code I am...
The Code should have been p0440 to p0457 or
p0465 to p0469...for the evap system..
I have to go with the information I have and I am sure it is correct..




That is not the map sensor on the firewall. That is the Vapor Management Valve. It is used for the Evap system. The Map sensor is integrated into the EGR valve along with the EGR control solenoid.

[grampaws]

I stand corrected the code reader was reading the previous code

and had not refreshed...the map code does come up correctly when the EGR
is disconnected and corresponds with what
Killed Kenny has indcated ...still not the MAF..
the Evap code did finally pop up!!

[SergntMac]

Very interesting exchange between professionals, thank you gentlemen! I am enlightened.

So, am I correct to draw a conclusion between my supercharger boost gauge and my Scangauge? is the MAP data I read my boost?

Thanks again!

[KilledKenny]

Very interesting exchange between professionals, thank you gentlemen! I am enlightened.

So, am I correct to draw a conclusion between my supercharger boost gauge and my Scangauge? is the MAP data I read my boost?

Thanks again!
Yes. Not sure what values you able to read with your scangauge but mine can read 2 MAP pids 1 vacuum and 1 pressure. I can also read fuel pressure from the FRP pid. Most Ford Returnless fuel systems have what called a Fuel Rail Pressure Tranducer. This Tranducer is use to monitor fuel rail pressure so that the PCM can duty cycle the pump to increse or decrease fuel pressure based on demand.

[ultravorx]

Just got my car back from the dealer. The work order states that i had a 0108 code which is a high voltage MAF sensor!!!! WTF is that? We all know that code mean a MAP sensor. So i'm just waiting for the light ot go back on and i'm going to hand it to the dealer. Interestingly enough, i looked at my MAF sensor, and its just as dirty as the rest of the engine, hmmm, it looks like they didnt even change it. But they did manage to charge the insurance $350!!!! When i asked about the light coming back on, i said would you just replace the MAF sensor again, the manager just stood there quiet. So, i really have doubts with this dealer. I cant believe this,
Frank

[ultravorx]

Well, as i predicted (knew) the light did go back on. he dealer said they will have to rediagnose the problem on monday. Interestingly enough, i told them its the same light and im not paying again, nor will i have them "replace" the same sensor. It really sux because im locked into that dealer with my extended warranty. I cant switch dealers, the Portfolio warranty says selling dealer within 40 miles. Oh well, see what happens,
Frank

[Smokie]

Well, as i predicted (knew) the light did go back on. he dealer said they will have to rediagnose the problem on monday. Interestingly enough, i told them its the same light and im not paying again, nor will i have them "replace" the same sensor. It really sux because im locked into that dealer with my extended warranty. I cant switch dealers, the Portfolio warranty says selling dealer within 40 miles. Oh well, see what happens,
FrankIt is pretty sad when the car can actually produce a code that tells the mechanic where the problem is: MAP and they change the MAF. It is possible the mechanic is dyslexic and can't read the difference between MAP and MAF.....or maybe he's just plain dumb.:lol:

[RF Overlord]

I cant switch dealers, the Portfolio warranty says selling dealer within 40 miles. Frank, I feel your pain...I get all antsy when the Blackbird has to spend the night in a strange garage, too...

Just a thought...sometimes it's worth the money to just PAY someone to fix it RIGHT the first time and avoid the hassle, waste of your time, and heartache. Save the warranty for the big-ticket items...

[MENINBLK]

It really sux because im locked into that dealer with my extended warranty. I cant switch dealers, the Portfolio warranty says selling dealer within 40 miles.

This is why we stress that buying a FORD PREMIUM CARE WARRANTY
is so important !!!
You can take the warranty and go to ANY FORD DEALER !!!