Sudden death.....with codes

[JiFaire]

Missy is, as usual, dead right on this one...

Codes have a nasty habit of cascading; one problem causes another, and THEY tell 2 friends, and so on and so on...

Your initial code 17 was the OS fault; normally, when a 17 arrives as a result of poor opacity or fuel lubrication (yeah, I know, it shouldn't, but it does), you get 17, 18, 35, and sometimes 54. So the 68 and 86 were strange, here; not a 'normal' OS fault.

Finding it unplugged is not normal... that probably cascaded the whole works.

The clue here, incidentally, was the 17 re-appearing without cranking.

The problem with dealerships is they read the damn manual and assume it's all right, so if they get 10 codes, they down the engine and change 10 things, all at once - makes for nice repair bills.

Sometimes, you fix ONE blabbermouth and you can stop ALL the gossip in the neighborhood... likewise, fixing the main fault can prevent the cascade of DTC codes.

Faire's Rules;

1] - Always do the cheap/free stuff first. Grounds, connections, tests for LP, fuses, etc. If you do a major repair and the problem is still there (and turns out to be a loose wire) you're gonna be torqued.

2] - Fix one thing at a time - start with the (logically) most likely suspect (keeping in mind the cost), and then test. Did that fix other things as well?

3] - Use the codes and diagnostics with a little common sense... if it isn't logical, it probably isn't the problem.

 

[JiFaire]

I wonder if this is an side effect of the OS Bump. Because it should not have died with just loss of the OS. I can unplug mine and drive all over.

The problem may be that the TDCO with OD bump may be a few degrees off of actual at the crank. So when it tries to run just off the crank timing signal it has timing wrong and it can't run.

Can anyone else with an OS bump try running with their OS unplugged, and report back if limp mode works?

Now THIS HERE is a really good point... if the timing ends up outside of the 'range', things die right fast. Unplugging the OS sets a code, knocks the IP back to 'will run, just crappy' mode. The Optical Bump (never did mine, Bill Heath strongly recommended against it) changes the relationship between timing and injection event, no?

Hmmm.... must think this one through...

 

[Yachtcare]

I wonder if this is an side effect of the OS Bump. Because it should not have died with just loss of the OS. I can unplug mine and drive all over.

The problem may be that the TDCO with OS bump may be a few degrees off of actual at the crank. So when it tries to run just off the crank timing signal it has timing wrong and it can't run.

Can anyone else with an OS bump try running with their OS unplugged, and report back if limp mode works?

While this does seem to make sense, I can only say I've been driving the truck with the OS bump, and the TDCO at -1.76 for over a year now, with no problems or codes, until this episode.

If the truck can be driven without the OS harness plugged in, then there's no telling how long I've been driving around with it unplugged, either. Unless the 17 will set immediatly as a result, then I know exactly the place, date, and time it unplugged itself.

When I plugged it back in, the truck started immediatly, and has had no issues since........So, I dont know

But starting to think there may be another impending failure in the works?

 

[buddy]

17 and 18 will immediately report if its unplugged.

It will run fine with the OS bump, but maybe a side effect is it wont run without a functioning OS. This just means leaves you with $300 tow when it could have limped home. I can't say for sure if the OS bump did it, thats why I wonder if anyone that has done it has tested this scenario. Maybe redoing TDCO after an OS bump is the real problem. Need to set it when OS is correct, so relationship to crank timing is defined correctly for the PCM, then bump it.