Turbo Intermittent

I can not say why fault code did not pop up. your truck is century or Columbia?

 

2000 classic.

motor is 99 12.7.

edited
it is ddec4

 

your truck's instrumental cluster has display to show fault codes ?

 

No. It has a check engine (yellow) and shut down (red) in the dash and that's it. I have a bully dog that can read the codes and gives a brief description. Mine said "low voltage turbo boost sensor" something like that. And it shows the engine load as a % also throttle position. When it threw the code I could put foot to floor, it showed 100% and engine load 40%. Boost was less than 10 psi after sensor cut out.

 

low voltage turbo boost sensor ---> flash code 34
Flash Code 34 indicates that the engine Turbo Boost Sensor (TBS), see Figure "Turbo Boost Sensor" or Turbo Boost Sensor (2003 Engines), input to the ECM has dropped below 5% (normally < 0.25 volts) of the sensor supply voltage.
This diagnostic condition is typically:

1. Open sensor signal circuit
2. Open sensor +5 volt supply circuit
3. Sensor signal is shorted to sensor return circuit or to ground
4. Sensor +5 volt supply is shorted to the sensor return circuit or ground

))) you've had fault code 34.

 

Perhaps, I don't remember the code numbers ...