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go-west.., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1133
Experience:  Technican with 20 years experience focused on engines and electrical.
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Have a Frieghtliner with cummins with ISB with code spn 102

Customer Question

Have a Frieghtliner with cummins with ISB with code spn 102 fmi 2.
Submitted: 24 days ago.
Category: Medium and Heavy Trucks
Customer: replied 24 days ago.
2010 M2 106 with ISB 6.7L engine ser. 73071476. We have replaced sensor 2 times checked the harness multi times and replaced ECM. We may have the wrong pin out and or wiring diagram. This ck eng lite has been on a long time where it may lite relally dim in dash and its a diode type lite. We have a thoery its been on since truck was new or shortly after customer took delivery. Truck has 164,000 miles on it now. Took to dealer they said replace sensor and wiring harness, we can watch sensor move on meter and harness shows less that 5 ohms on each pin. Vin number 1FVACXDT3AHAW0468
Customer: replied 24 days ago.
Also intake manifold #1 pressure is that the sensor b4 turbo in the air horn?
Expert:  go-west.. replied 23 days ago.

good morning

The intake manifold 1 pressure/temperature sensor is located in the air intake manifold.

as for the dim cel on the instrument cluster that is a know problem and you are looking at diode leakage,the only fix for that is replacing the cluster..

as for trouble shooting this code,you will need insite,do you have??

if not, here are some possibilities..

This diagnostic consists of two parts. At key OFF, the sensor readings for intake manifold pressure, barometric air pressure, oil pressure (if available), and exhaust gas pressure are compared to each other. This fault code occurs if the intake manifold pressure sensor reading is different from the other sensor readings. This check is only done once after the keyswitch is turned OFF. This fault can also be set active when the intake manifold pressure is too high or low for the current engine operating conditions when the engine is running. The ECM compares the intake manifold pressure reading to turbocharger speed to determine if the pressure reading is valid.

Possible causes of this fault are:

  • A damaged turbocharger speed sensor
  • A damaged barometric pressure sensor
  • Leaks in the air intake system between the turbocharger and intake manifold
  • Restriction in the charge-air cooler
  • A damaged intake manifold pressure sensor
  • A damaged turbocharger compressor intake temperature sensor.
Customer: replied 23 days ago.
The pid on our snap-on pro link ultra reads "sub system" error like ecm does not see value.??
Expert:  go-west.. replied 23 days ago.

Does it say fault 1 on your odometer display ?

I would use that instead of the reader

You can get the fault codes off the odometer display by pushing the mode button

Customer: replied 23 days ago.
Truck shows no codes on dash, but check engine light is on. And we did replace dash to fix light problem
Expert:  go-west.. replied 23 days ago.

If the dash odometer display shows no faults there are none active

is the cel light on bright ? or dim ?

Customer: replied 23 days ago.
Expert:  go-west.. replied 23 days ago.

ok good

if you have no way of clearing codes then it will take 4 drive cycles to clear.

it has to do with the onboard diagnostics

4 drives are defined at 4 drives at 4 hours each

the light was on but there are no codes so now it is starting the drive cycle process.

Let me know if you have anymore questions..

Customer: replied 23 days ago.
This snap-on scanner was 10k it should clear a code but it want should you say drive 2 drive cyc you gave and they may clear or should clear code?
Expert:  go-west.. replied 23 days ago.

its better to clear it now if you can

Not all shops can do it

Customer: replied 23 days ago.
Ok let me pass this on to my tech, thanks for now
Expert:  go-west.. replied 23 days ago.
Customer: replied 23 days ago.
We have never heard of a drive cycle this long b4 but we don't know the truck is derate runs because of code I'm assuming.
Expert:  go-west.. replied 23 days ago.
Customer: replied 23 days ago.
the derate will go away when code does?
Customer: replied 23 days ago.
Got more 1 question we made repairs and then put new ecm in and International change it out and did reset or flash but code was still there. did they just copy what was in old ecm if not where did code come from?
Expert:  go-west.. replied 23 days ago.
It will
Can't you clear it with you reader?
Customer: replied 23 days ago.
no, with the snap on or killing the bat comes right back
Customer: replied 23 days ago.
Might just had a holy crap moment, the pid just start reading a value and the code was able to clear. we are putting it back together and test drive
Expert:  go-west.. replied 23 days ago.
Keep me loop
Customer: replied 23 days ago.
Update,we are able to clear code with scanner it will idle no code returning. However when you drive or put pedal in WOT we are now getting spn 108 fmi 2 where b4 we had code 102/2. Also watching the pid while driving the intake manifold #1 pressure has a value then it will go to "sub-system error" and the code will set. The truck diagnostic still shows to active faults
Customer: replied 23 days ago.
We found sub system error means the no value so the it looks like the pid is loosing its value when you start driving. But at idle it will run fine. Should baro sensor have a value around 14 when the truck is off? this truck reads around 6.
Expert:  go-west.. replied 23 days ago.
It's 14.7 at sea level
If you are close to the sea then yesAre you?

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