I am having a very strange boost problem and speedometer quit working
I don’t think they are related tho

2005 f250 SD
egr delete
SCT tuner
converter removed
arp studs
head gaskets done last winter

After starting the truck and warming up I take off and have good boost up to 28psi and it takes off great, a mile down the road hit it again and it will only boost 16-19psi and then it stays that way, (only boosts up to 16-18psi when I get on it) no matter how far I drive it. It runs great and starts great but just lacking the normal power. Noticed this after I had not drove it for a week or so and tried to start it and the batteries were dead. So I charged them but it took a few tries before the batteries were strong enough to start it. (something drains the batteries while it sits) Then I noticed the low power or boost problem and the speedo quit, but it was acting up earlier this summer and fixed itself. I have done a lot of trouble shooting trying to figure this out. while on a test run today I noticed the normal boost at first then low boost a mile down the road, so I pulled over and shut it off and restarted it and I have 28psi again at first then a mile or so max 19psi this is after I let off and hit it again. So every time I shut it off and restart I get good boost and seemed the more I did that the longer I had good boost, but still drops to max 19psi down the road.

everything I have tried so far:

-reprogram sct
-reprogram to stock
-reprogram to street tune
-checked for turbo boot leaks
-checked Map hose and intake fitting
-checked EBP and took EBT line off and checked it
-unplug turbo and plug it back in
-unplug ebt and plug it back in
-had the turbo checked last year when I did headgaskets, but I pulled it off again and cleaned it myself, looked clean and unison ring looks great, the vgt moved freely by hand and turbo changes when unplugged
-tried the turbo relearn procedure
-checked fuel pressure was only 45psi at idle and dropped to like 35psi under load, got the blue spring kit and oil psi is 65psi at idle and 55psi under load

after all this still doing the same thing

later today I am going to try a map sensor off my buddys truck and see if that is it

any other ideas?

on the speedo not working, it started bouncing and going to zero. Now it is just sitting below zero.

-Tried the gauge diag by turning on the truck while holding the trip reset, gages all worked
-checked connection at pumpkin speed sensor
-unplug and plugged back in the wheel speed sensors

next I am going to try the pumpkin speed sensor from my buddys truck, but my ABS light is not on like others when that goes bad??

thanks ahead of time for any help

codes
p0500 speed sensor
p1299 intake air temp 1/2 correlation

 

You might try pulling and cleaning the IAT2 sensor. It's on the passenger side intake runner. Look at it closely, the business end is a small round plastic cage with a small thermistor inside. The cage can completely clog up and make it look like it's supposed to be that way. Clean it out with a toothpick and a brush (a gun cleaning kit with plastic picks works great) don't use solvents. Boost limiting is one way the PCM dials back the motor if there is a significant code. Resetting on the restart is a good clue and if the only code is IAT related that makes it a good place to start.

 

Ok I’ll pull it tomorrow, It almost seems like it goes into a limp mode, but no wrench light on.

 

you need a Gauge to check the sensors it must read live data so ScanGaugeII to address the Boost issue
BARO
MAP
EBP
VGT%

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there is your speedo issue^^^

Not shure what speed sensor is (A) you should be able to check it with a DVM but im not shure what type sensor it is so IDK what to set the DVM at

Your EGR Deleate maybe the cause of IAT 1&2 corrlation
You nee to check these 2 after 12 hour cold soak they should read the same at KOEO
So SGII again for this one

Got to have gauges to play

 

Just looked up your DTC P1299 is NOT FOR DIESEL TRUCK

P1299 Cylinder Head Over Temperature Protection Active


This DTC is for a GASSER^^^^^^^^^^^^^^^


Check this one again^^^^^^^ its NOT IAT 1 & 2 Corrlation

 

cleaned the IAT2 sensor, it was gunked up but not as bad as some I read about, the p2199 code is gone and now only have the p0500 speed sensor. the truck is still doing the same thing. Good boost for a mile and if I am on it at that point I can feel it drop the boost down like something is putting it in a sorta limp mode??? the speed sensor not working wouldn’t cause this?

 

Also swapped another map sensor in from my buddy's truck. Made no difference. Also swapped the speed sensor in the pumpkin with my buddy's truck. Speedo still out.

 

scan gauge 2 on its way!

 

Thats the DTC

What did you do erase the Codes and P0500 only one to come back

It could put in limp mode not shure thats a Cheezit or Mike or Bismic or vince maybe some others IDK Question

Will see what SGII says for Boost Psi

 

A p0500 will cause limp mode type condition after a minute or so ive seen it on my own 6.0 and others ive worked on check wiring to vss or sensor.

 

I am almost convinced the speedo not working is causing a limp mode

Checked wiring can’t find any chaffing. Traced the red/purple and green/black wire from sensor to the ABS block. Unplugged grey connector with the red/purple and green/black wires from under the ABS block, also unplugged the VSS sensor and looped the two (red/purple and green/black wire) together at the sensor harness. Then I checked for continuity at the grey plug under the ABS block and I have continuity. Then I pulled the loop wire and no continuity. Also checked each wire to ground while unplugged and neither was shorted. Checked the ground 105 and the ABS fuse (mini fuse #11) even cleaned them and reseated and bolted.
Found a bulletin about wire chaffing behind the degas bottle to the wiper motor on a brakeline clip. It was all good
took the VSS sensor out and and look at the tone ring for damage, looked good from what I can see.
So I pulled the OSS speed sensor out of the transmission and ohmed the three prongs out and every combination was an open. I see people say the OSS would throw a different code but it should have 700-1800 ohms between pin 1 and two. It is confusing I read people stating the speed signal comes from the VSS in the pumpkin and a few say it comes from the OSS in the transmission??? Could this be my problem?

 

any ideas on the OSS?

 

I'm with you. I thought I understood the the speedo signal came from the sensor in the pumpkin. When you did the odometer test did you set it to display speed ad take it for a drive? Might give you a heads up if the instrument panel is having issues. Check the step in red below, and the metric one below it.


Odometer Trick:

1.With the key in the ignition and in the off position press and hold the odometer / trip button.

2.Turn the truck to ‘On’ but do not start the truck.

3.After a few seconds the gauges will sweep from nothing to max, release the odometer / trip button.

4.The odometer should now read ‘GUAGE’, you are now in a information mode.

5.Start the truck

6.Now every time you press the odometer / trip button it will cycle through the information available.

7.When you shut the truck off the odometer will go back to showing mileage.

GAGE - Carries out gauge sweep of all gauges, then displays the present gauge values. Also carries out the check sum test on ROM and EEPROM.

All segments illuminated.
Illuminates all odometer segments.

bulb
Illuminates all micro-controlled lamps and LEDs.

r ####
Returns to normal operation of all micro-controlled lamps and LEDs and displays hexadecimal value for ROM level (used when requesting assistance from the hotline).

nr####
Displays hexidecimal ROM level and type as stored in non-volatile memory (NVM).

EE ##
Displays hexadecimal value for EE level (used when requesting assistance from the hotline).

dt ####
Displays hexadecimal code for the final manufacturing date.

###C
Gas engines display last temperature gauge input value from SCP, temperature gauge will indicate present temperature. Diesel engine displays present temperature analog/digital input in decimal as a ratio, temperature gauge will indicate present temperature.

dtc ####
Displays a 16 bit DTC in hexidecimal format. DTCs displayed are those detected in continuous operation not during self-test.

EnG
Displays English speed value being input, speedometer will indicate present speed.

m
Displays metric speed value being input, speedometer will indicate present speed.
tAc Displays the tachometer value being input to the instrument cluster. Tachometer will indicate present rpm.

FUEL
Displays the present analog/digital fuel level being input to the instrument cluster as a ratio.

OIL
Displays the last analog/digital reading of the oil pressure switch contact resistance, oil gauge will indicate present level.

br
Displays the brake fluid level in an analog/digital ratio value.

bAt ##.#
Displays present battery analog/digital voltage.

rhEo
Displays present hexadecimal pulse width modulation (PWM) dimming input.

rhi, rhS, rho
Alternating 1 second display of pulse width modulation (PWM) input duty cycle, SCP hexidecimal dimming step, output driver counts in hexadecimal.

Cr
RUN/START sense circuit check.

PA, Pb, PC, and Pd
Displays 8-bit hexadecimal value for the Port A, B, C, and D readings (used when requesting information from the hotline).

PE0-PE7
Displays 8-bit hexadecimal value for the Port E0-Port E7 in analog/digital readings

07-19-2007 | 04:43 PM
superv10
I have an 05 with the 3 buttons (Info, Setup, Reset)

You have to hold the Setup and Reset buttons at the same time, then turn key to on - you will see TEST and as soon as you do, let off the buttons and then start the truck - press reset to cycle thru all the options...

07-20-2007 | 12:42 PM
EZ-Ford
There also appears to have been a change when the went from the 1 line to 2 line Odometer display. Below are all the items that list on my truck (2 line display). I have added the descriptions, based on the previous information where it seems to fit. A few are still unknown. Specifically, the item listed as OIL, shows as all zeros (000) in my display. So if this is pressure as was previously, boy does that worry me (though my pressure gauges shows good). The numeric entry (on mine 001624), I don't know what that means or if it will be different with a different truck.


When you guys check yours, update this list below and lets see if we can put together a complete outline that can then be sticky'ed to a tech folder.


Display ..........Description
=======================
SWEEP GAUGES ..Full deflection sweep
ALL ...........Odometer segment check
BULB ..........Warning light check
PF #### .......
SF #### .......
001624 ........
KEY IGN # .....Ignition key-in status
ROM #### ......ROM level
NR #### .......ROM level and type
EE #### .......EE level
DATE #### .....Manufacture date
CF1 #### ......Configuration setting
CF2 #### ......Configuration setting
CF3 #### ......Configuration setting
CF4 #### ......Configuration setting
DTC #### ......Cluster diagnostic trouble codes
MPH ###.# .....Speed MPH
KPH ###.# .....Speed KPH
TACH #### .....Tach RPM
FUEL AD ### ...Fuel level ratio - ?
FUEL P ### ....Fuel level - ?
F INIT ### ....
C TEMP ### ....Coolant temperature degrees Celsius
ODOM ### ......Odometer input
OIL ### .......
BATTERY ### ...Charging system voltage
PWM ...........
DOOR 1 # ......Driver Door switch status
DOOR 2 # ......Pass Door switch status
SEAT BLT # ....Seat Belt status
CHECK ENG # ...
PA – PW .......Port Data
PAD0 – PAD1 ...Port Data
AD00 – AD17 ...Port Data

 

already had tried that with the trip odometer and no speed registered

 

here is some of the readings with the scan gauge 2
haven’t had a chance to drive it with the scan gauge 2 in it

BAR
on 14.2
idle 14.2
high idle 14.2

EBP PSI
on 14.7
idle 17.4
high idle 22.6

EPV
on .89
idle 1.25
high idle 1.52

FLP
on 11.5
idle 13-13.5
high idle 12.5-13.5

FMP
on 48.5
idle 48.5
high idle 48

IA1
7680

IA2
104

MAP
idle 14.5
high idle 17.8

VGT
idle 74
high idle 45

I still need to check the others under load

most of the stuff seems in range or very close except AT1 not sure?

also would the OSS make the speedo not work?