Engine runs: ICP Disconnected!

Keith Browning · July 28, 2005

2005 F350 6.0L reportedly stalling with ICP codes, I can't duplicate the concern. Anyway, checking the connector and harness with the engine running and PID monitor up on the WDS. .I disconnected the sensor and it kept running. What's even better is it started back up with it disconnected too. Default idle ICP was 875 and increased with the AP.

When did this start? I gotta check the other years for this.

mpatron · August 3, 2005

That's why it is advised to pay more attention to ICP voltage. It is telling what the sensor sees, especially if you are looking for a standpipe check valve failure with PID data.I believe diconnecting it is also part of no-start diagnostics.

Keith Browning · August 4, 2005

Yes, but what changed? It used to be that if you had an open circuit related to the ICP sensor then engine would quit running and would never start with it disconnected either. This would in my opinion represent a software change. I see an advantage to this. An electrical failure is not going to disable the truck and leave the owner stranded. Would you call this the diesel version of FMEM?

You know, now that I think of it, these things would probably run better and a lot more reliably if fuel rates and timing were controlled using fuel tables alone and the sensors were used only to monitor the system... sort of like using the EP and ICP sensors like oxygen sensors to make overall adjustments to fuel trims and monitor the injection system as a whole.

mpatron · August 4, 2005

That makes about as much sense as just using MAP and BARO and AP to control boost instead of that *&$# EP sensor. What blasphemy! Next thing, you will think a VGT position sensor like GM uses is the way to go. /forums/images/%%GRAEMLIN_URL%%/banghead.gif

Keith Browning · August 5, 2005

VGT position sensor

Wowwwwwwwwwwwwwwww!

And I thought FORD was the company with "the better ideas!"

drford · August 15, 2005

2005 F350 6.0L reportedly stalling with ICP codes, I can't duplicate the concern. Anyway, checking the connector and harness with the engine running and PID monitor up on the WDS. .I disconnected the sensor and it kept running. What's even better is it started back up with it disconnected too. Default idle ICP was 875 and increased with the AP.

When did this start? I gotta check the other years for this.

well i had a huge head ache the other day the 2005 will run without any v ref signal unit came in with a shorted pedal assembly from an aftermarket body builder pulled codes had one for every sensor using v ref monitored pdis no v ref at all sensors unit still ran fine phoned hot line they told me the 05 MY will run with no v ref signal took for ever to diag the issue and this will make it harder

PWRStrokeMaster · November 4, 2005

The way the 6.0L calibration has worked is that by diconnecting sensors the pcm will go into a "default mode" for that system. If you unplug the icp, the pcm has no back feed at all so it sets the ipr and icp at a preset value and as long as the system can produce the desired pressure, it will start and run. same way to check for a surging vgt by disconnecting the ebp sensor. it will set the vgt to a "default" value. I however do believe that a vgt sensor would be nice. It would save diag time and dealers getting charged back for unnecessary turbo replacement.

HGM · November 4, 2005

Guys,

Have you never seen the Low Idle Stability test? It has been arround since early 7.3L PS. You unplug the ICP and check to see if your idle quality changes. This puts it into a default mode to check if the sensor is causing the issue or if it is really pressure related.

Keith Browning · November 16, 2005

Have you never seen the Low Idle Stability test?

Yes but that test has you disconnect the ICP sensor with the engine already running. The 7.3's never started with the ICP disconnected and to the best of my recollection, neither did the 6.0's until now.

Jim Warman · November 20, 2005

I can recall sometime in early 03... we were chasing a problem I can't even remember... hotline had me unplug the VGT and the ICP and go for a road test... The truck did start but fell flat on it's face when you tried to drive it...