Discussion:
Code 27

Hello folks
2005 CAT C-6000 with Nissan 2.5 on LPG (Ser.# AT83F00151):
Intermittantly sets code 27 (crank sensor) but sensor wave form seems ok (although voltage is higher than spec).
Another tech here says this happened before and a coil pak solved it...for a while.
Now it's back (miss and code 27).
Another coil pak (different cyl) and all seems ok again.......
Why would a bad coil/miss cause it to set code 27??

Thanks! -Jeff
  • Posted 18 Oct 2011 05:47
  • By JeffreyJay
  • joined 17 Aug'11 - 5 messages
  • California, United States
Showing items 1 - 4 of 4 results.
Thanks, that is what I ended up doing to find the faulty coil as my ign. PU won't really get in there. The large gaps were on the (NGK)plugs coming out. Yeah, my parts dude tried to give me NDs or something...wrong overall length as well as protrousion.
NGKs installed with one coil as stated....unit is still working fine.

Thanks again all!
  • Posted 27 Oct 2011 03:43
  • By JeffreyJay
  • joined 17 Aug'11 - 5 messages
  • California, United States
There was a service bulletin from Nissan about that problem. That code is almost always caused by a misfire due to a bad coil. The procedure to test the coils is to start the engine and disconnect the coils one at a time until you find which coil the engine wont run on, and they will run on one cyl firing with a good coil and plug. I usually replace the bad coil and all the plugs. NO MATTER WHAT SMH OR ANYONE ELSE TELLS YOU, ONLY USE THE OEM NGK PLUGS! FYI most engines that use coil on plug ignition only work right with the OEM spark plugs.

Edit: I've never seen an oem NGK plug with a bad gap out of the box, but it never hurts to check
  • Posted 22 Oct 2011 09:28
  • Modified 22 Oct 2011 09:33 by poster
  • By fixitandy
  • joined 23 Mar'09 - 81 messages
  • Pennsylvania, United States
This industry has a lot of ups and downs
Interesting thinking that this causes the crank pos code to set...it is an explanation.
I did replace the plugs and one coil pak and it has been fine. The plug gaps were huge as the electrodes were almost flush with the porcelains. 3k
Thanks!
  • Posted 22 Oct 2011 00:43
  • By JeffreyJay
  • joined 17 Aug'11 - 5 messages
  • California, United States
my personal wag has to do with stray spark plug voltage, and I think it is worth it to the customer to change all the coil packs and spark plugs and gap the plugs. how many hours on this thing?
  • Posted 18 Oct 2011 09:43
  • By edward_t
  • joined 5 Mar'08 - 2,334 messages
  • South Carolina, United States
"it's not rocket surgery"

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