Community Forums

Kountry_star · 03-25-2019, 05:32 PM

We have a 2004 Neumar on a freightliner XC, Cummins ISB. Coming home on our last trip got a very intermittent check engine light. Would only stay on 10-30 sec. at the most. Left codes: Lock up clutch pressure indicator out of calibration and a seemingly unrelated code of: Variable geometry turbo charger actuator out of calibration. Had it checked in Alamogordo, NM and again in Colorado Springs they said every thing seemed / checked fine "don't worry about it", cleared the codes and off we went. On the 1800 miles home to Upper Michigan came on half a dozen times a day for no more then 30 seconds. Sometimes going uphill. sometimes down, stopped, cruise etc. etc.. Any ideas before I spend another $360 to get it reset. Being an old airline mechanic I know something is triggering codes! What I don't know is what harm will / can be done by "don't worry about it"?

Mr_D · 03-25-2019, 05:36 PM

Start checking for corroded connectors and grounds between the engine and ECM. Also look for connector pins that might be out of place. Sometimes the pins can move and not make solid contact.

oscarvan · 03-25-2019, 06:39 PM

Yup.... As an A&P you should be skilled at "re-racking" and checking canon plugs.....

There's a lot of them down there, and some of them are quite exposed to being hit by something on the road and/or getting dirty.

Skip426 · 04-05-2019, 07:15 PM

First , I'd ask you to consider a , Silver Leaf or Scan Gauge D, so you can read and erase the codes yourself.
Cheaper than the shop charge.

There is a post with pictures , of what another member found when his ISB started throwing the Turbo Code , I'll track it down and post a link.

Skip426 · 04-06-2019, 03:02 PM

Finally found my notebook with the link to the turbo issue.

NOTE; this is only a possibility , as your problem may be all electrical.

http://www.irv2.com/forums/f123/2008...ht-338508.html

Also in case your interested in the devices.

www.scangauge.com/products/scangauge-d/

www.silverleafelectronics.com/node?page=2

Good luck and safe travels

Kountry_star · 05-19-2019, 09:43 AM

Think I found one of the problems. Apparently I've got a sticking actuator on my variable geometry turbo. Will have to take apart, clean then readjust the actuator. Some have said just install a rebuilt turbo and be done with ($1200 difference in cost). Think I will go for the clean first before going for the replace / higher cost. Still have to figure out the "lock up clutch pressure indicator out of calibration". Cleaning grounds (many) and reracking cannon plugs (many more) has had no effect. Additional ideas are welcome!

RRGarcia626 · 05-20-2019, 03:02 PM

Had same issue with my ISB. Had actuator checked and replaced. Problem persisted and turbo was replaced. This fixed the problem. Mechanic initially thought actuator would do it, and when turbo also needed changing, only charged for part. Purchased turbo from Cummins. Not cheap but been year with no issues. Problem was from soot build up.

rrtribble · 05-20-2019, 05:04 PM

Just a thought based on my recent problem. Intermittent check engine and stop engine lights always when accelerating up a hill or passing. Finally lost turbo. C7 got me home with no problems but couldn't pass anything. Codes indicated actuator problem but the real problem was my turbo has frozen up. Also discovered a rust hole in the turbo exhaust that may have caused the turbo to freeze.
Fixed now and running great.
If not electrical the turbo is normally the problem.
Best wishes - Richard

RRGarcia626 · 07-18-2019, 09:02 PM

Had similar issue with my 2006 Tiffin with Cummins ISB. Code showed actuator issue. Had cleaned and calibrated. Continued and was told actuator need to be replaced. Changed part and problem consisted. Spoke with mechanics and they could not replicate problem in shop. They then took RV out and drove up and down hill while connected to laptop. Showed that turbo was only opening to 89% and this was causing check engine light to come on for short period of time and only while under load. Replaced turbo and actuator and problem went away. Turbo and actuator had build up of soot.

Kountry_star · 07-19-2019, 09:19 AM

Thank you for the imput. As you said pretty sure it is caused by Turbo. We just returned from an emergency trip out west. On the way out we hit a torrential downpour (lasted about 15 min, seemed like hours). Check engine light came on and stayed on. Shortly after the downpour light went out. Checked and cleared codes (same codes registered). Next 2800 miles light hasn't come on and no codes have been recordered. Not sure what that means??