I have a 1997 F350 CCab, SRW 5spd that sometime in the past year the check engine light comes on and stays on.. I hadnt hooked this truck to a trailer in a long time so I didnt really notice any real lack of power... til last weekend when I hooked my fifth wheel camper to it.... WOW ! I think on the Interstate an old 6.2 Chevy could have out pulled it.
It's sitting at a diesel shop in town because I've got too many other things to wrench on besides my own truck and my scanner is broke and my new Auto Enginuity hasnt arrived. Anyhow, my friend in town scanned it and it came back with a ground circuit fault in the MAP sensor..... like a "smart" guy... got one at Bumper To Bumper... put it in and the truck wouldnt even start... unplug it, plug the oem one back in... start it, unplug it and the truck would stay running... while running, plug the new one in... instantly the engine dies. Now....next, I took that one back , refunded as faulty... got one at NAPA... exact same issues as first new one... truck wont run with it.... OK NOW I'm ticked... went to FORD ! Bought a brand new Ford / Motorcraft Map sensor... it took 3 days to get one from the warehouse..brought it out to my buddies shop.. open the box... it looks EXACTLY like the aftermarket ones did and NOTHING like the OEM one... only difference from Aftermarket is it has a Ford logo and a Ford part number... OK so I plug the new Ford one in.. engine will not start... same as before... now my diesel shop buddy is scratching his head big time... course this happened right at closing time for the Ford dealership in town and because it's the weekend, everyone split and didnt want to take the time to see if they actually got me the right part... I live 65 miles from town and am quite tired of chasing parts that dont work... Anyone ever have this problem"?? The original OEM sensor has a small crack in the plastic body, near the electrical connector... probable cause of the check engine light and poor performance under load. All tips / fixes welcome !

The OEM Original MAP sensor PN E7EF-9F479-A2A... engine runs, check engine light on and has poor performance under load (hills with trailer) and has small crack in housing.

The new Map Sensor from Ford that doesnt work period, no start, nothing !
PN # F4TZ-9F479A

 

Correcting an error... I said it was a ground circuit fault in the MAP sensor... that's wrong... I'll have to call the shop tomorrow and get the codes and post them here... I dont know what I was even thinking... MAP has no ground...best I remember from looking at schematics.

 

They are giving you the correct part F4TZ-9F479-A (94-98 digital)
according to the link in my signature. I will check the one on my truck
to see if it really is correct.

I just googled your original, E7EF-9F479-A2A.
It seems it is used in europe for:
1989 to 1996 Fiesta 1.1 and 1.3L Gas engines
and 1989 Lincoln Mark VII LSC 5.0L Gas

Wow, that's messed up.
Someone may have re-wired your truck to accept the gasser MAP IMO.
Gassers are vacuum operated vs diesels that are pressure operated!

 

Scott, sounds like you are killing the vref (5 volts) to all your sensors when you plug in the correct MAP. Vref that runs the MAP also controls Accelerator Pedal sensor, BARO sensor, CPS, EBP and ICP. Check you MAP sensor plug carefully. There are three wires ...

BRN/WHT is vref (5 volts)
LT GRN/BLK is output to PCM
GRY/RED is signal return or ground

Viewing from the front of the truck and going left to right the color code of the wires on the plug should be GRY/RED .. LT GRN/BLK .. BRN/WHT.

 

We bought this truck last year...traded a 95 Dodge Cummins 2wd dually for it, so I really dont know much history on it other than the guy that I bought it from had to replace a bunch of stuff under the hood because the battery cable that ran between the right and left batteries, shorted out on something and started a fire. I think he replaced the entire engine harness back in 2003 and it had been an everyday driver. Truck only had 120k on it when traded for it.
WOW ! a gasser MAP?? GEEZE I actually thought it was OEM because the end numbers - or part of them ... are the same. 9F479A. I'll call Tim and have him look closely at the wire color and see if he can check MAP pins and main plug pins for continuity, shorts, etc.

 

Hey Everyone... Special thanks to Cuda Jim and Hussler for helping me figure this one out....
I've tried several MAP sensors on this truck and with any of them... it wouldnt run. Tried a new OEM MAP sensor.. same thing... It ran just as well without a sensor in it as it did with what turned out to be a gasser sensor that the last owner stuck in it.
After Husslers last post, I started checking the MAP harness... about a foot and a half down the harness which was neatly in that plastic looming was two splices.. pretty as you please.. nice solder and heat shrink job too.... One Problem.. the guy that did it musta been color blind. In the splice the brown/white wire coming from the main harness was spliced to the red /gray wire going to the MAP Sensor plug in... and the Red/Gray wire from the main harness was spliced to the Brown/ White wire going on to the MAP plug in.... effectively KILLING VREF when plugged into the correct MAP...
Once I switched the wires back to their correct positions and installed a new OEM MAP... it fired right up... seems to fuel right too. I did have a BPS that showed bad ( 50 psi backpressure at idle will defuel a bunch too ) now the ole truck runs about as good as any PSD I've ever driven that didnt have a big chip in it. THANKS TO EVERYONE !! By the way.. my codes that indicated poor cyl contribution on 4 cylinders when we ran Auto Enginuity on it at my buddies shop,went away once I got the new MAP and BPS installed... I'm sold on that PC software now...I put in an order today for it, with the complete domestic extended package for Ford, Dodge and GM

 

Glad you got her fixed
That's just nuts! I can't imagine why someone would re-wire the MAP like that??
And then put a gasser MAP on a diesel. Oh well...

 

Whats really weird is my OTC scan tool that I bought just last year couldnt find any codes AT ALL.. and couldnt detect that the MIL light was on. Found out later why... 1996 and 1997 3/4 ton and 1 ton PSD'sare fully OBD1... there's not any generic OBDll archetecture used in these two model year Fords, unlike everything else 1996 and later. Most everything else 1996 and later had basic OBDll and vehicles 8500lb gvw and higher had some combination of OBD1 & ll plus OE model specific codes that generic readers cant detect.