[ddog]

SES with Code 1275 questions and How do you open the IDM?

Well the code scanner confirmed what I determined with the "finger test", my problem cylinder is #5. A little back ground, the truck went from running great to running really bad and setting the SES light in a matter of less than 2 minutes I would guess.

From the PCED manual Code 1275 indicates a low side to high side open in the circuit between the IDM and the injector. This is the only code I have. KOER, have no running codes and it did the self test thing OK.

To date I have visually inspected the UVC injector harness on right side, ohmed through the connector at the VC and ohmed through from the IDM connector, wiggled stuff and can find no "open" in #5 (or 1,3,7 for that matter). Inspected IDM connector as well.Checked for the rubbing on valve cover thing(although that should give the short to ground code, not 1275). PCED says at this point replace IDM.

Any suggestions on what else to check before hunting down an IDM?
Anyone have a harness check good with ohm meter, but replacing harness fixed the problem?
In another thread it was posted a bad injector won't set an SES light, Is this true?

and last

How do you open the IDM? I cut the sealant bead and pryed on it a little but didn't want to mess it up. Is there a trick to it? Want to check for water/internal corrosion but can't get in there.

Thanks!

ddog

 

[klhansen]

Re: SES with Code 1275 questions and How do you open the IDM?

Have you ohmed out the injector solenoid itself? It's possible your problem is there.

Also eyeball the VC gasket pins closely for burnt or corroded connectors.

As far as opening the IDM, you just need to pry the cover off, trying not to break the plastic (don't ask how I know this /ubbthreads/images/graemlins/crazy.gif). There's a sweet spot right near each end of the connector where you can get a small screwdriver in to get it started. That being said, I doubt that you'll find a water issue in the IDM. If you do open it, be sure and get some grey International sealer (like used on the oil pan) to reseal it.

 

[MADVAN]

Re: SES with Code 1275 questions and How do you open the IDM?

dog
The 1275 is for the #5 inj. With this in mind ckt#1087 (o wire) should be good due to 1,3,7 inj are ok. Did it pass an ohm test from the #5 inj to pin #8 on IDM. Ckt#559 (T/BK wire)? Wiggle wiring during a continuity test end to end (ckt559)? If so i would swap 2 coils from the inj to see if code changes with the swap. On a cold test it could test fine and a whole nother story when hot if its a coil.

Bill

 

[ddog]

Re: SES with Code 1275 questions and How do you open the IDM?

Kevin/Bill Thanks for the replies!Would have gotten back sooner, but DSL down at home and off work a couple days.

[ QUOTE ]
Have you ohmed out the injector solenoid itself?

[/ QUOTE ]

I have not, but I thought that is what I was doing when checking continuity from the IDM connector with everything plugged in. IOW I unplugged IDM and checked between Orange (High side) and Tan/blk (#5) and got 3.2 ohms, and wiggling the harness and connectors right to the VC didn't change or show intermittent open.

When I had the VC off I ohmed through the gasket connector and unplugged connector on injector side and ohmed through the UVC harness with same result. I did not unplug the UVC harness from the injector to isolate it and check injector solenoid by itself.


[ QUOTE ]
Also eyeball the VC gasket pins closely for burnt or corroded connectors

[/ QUOTE ].

I'll recheck that, Checked the up pins in the gasket but did not pull gasket off to check the ones pointing away. That being said the harness connectors on both sides looked really good.

Got the IDM open and found no water,corrosion or any obvious bad components, no discoloration or hot spots on board etc, not that it means anything.

[ QUOTE ]
Did it pass an ohm test from the #5 inj to pin #8 on IDM. Ckt#559 (T/BK wire)?

[/ QUOTE ]

Yes, 3.4 ohms between orange and t/bk going through the IDM connector. Wiggling did not change it. I did not unplug the connector at the injector and check the tan/blk by itself, but figured it was good if continuity was going through the solenoid and back on the common(orange).

In terms of the cold engine Vs Hot, It runs on 7 from a cold start. After clearing code sets SES immediatley upon start up. The way I figured the problem was on #5 before the scanner was the finger test. Started engine and after idling for a bit put finger on the maninfold outlet near the head one by one. #5 was cold when the rest were getting warm to the touch.

Swapping solenoids is a good idea, just need to borrow scan tool again to re-check.

Will recheck everything, but as of yet can't find an open in #5 ckt.If there is no open and solenoid swapping doesn't move things around, than does this mean swap the IDM?

Thanks Very Much!

ddog

 

[ddog]

Re: SES with Code 1275 questions FIXED !!!!

It turns out my single 1275 code (open in #5 circuit) turned out NOT to be wiring,UVC harness,or IDM. Replaced the UVC harness anyway because it was cheap although I found no fault with the original and still no change.

So you ask, if not any of those what is it...? The screw for the poppet valve under the #5 solenoid had come lose. Why the IDM sees this as an open circuit is beyond me, because I OHMed myself to death and could never find an "open" circuit. Remember if wiring is good, the PCED manual condemns the IDM.

Anyway, tightened the screw, (ground down an E6 star socket which worked but if there is such an animal, I think the correct size would be E5)put everything back together and no miss and no SES light any more.

Would not have figured this out if Madvan hadn't suggested swapping the solenoids between injectors. Pulled solenoids off 5 and 3 and immediately saw that 5 was loose compared to 3.

Runs like a champ again although I wonder how long before it loosens again /ubbthreads/images/graemlins/shrug.gif ? Time for new thread on injector repairs.....

Thanks all!

ddog

 

[MADVAN]

Re: SES with Code 1275 questions FIXED !!!!

Cool Dog.
Use some lock tight on the threads.

Bill

 

[ddog]

Re: SES with Code 1275 questions FIXED !!!!

[ QUOTE ]
Use some lock tight on the threads.


[/ QUOTE ]

Now you tell me /ubbthreads/images/graemlins/grin.gif .... Actually I was wondering about that. Right now they are just PFT, so far so good. Which threads? All of them, Solenoid and poppet? I did the repair with the injector in the truck. Actually I loosened the 4 screws under the solenoid valve also to see if that part came off, but I guess the poppet screw has to come out in order for that part to come off. Can you pull the poppet screw all the way out (to lock tite it)with out pieces falling off on the blind side? which loctite Blue 242 or Red 252? Probably should start injector repair thread.

thanks,

ddog

 

[MADVAN]

Re: SES with Code 1275 questions FIXED !!!!

242

Bill