Need DDEC codes checked.

opus · December 22, 2013, 01:59:06 PM

I've a friend in S Ga with a 6v92. He needs to get it on a machine and see whats going on. Can anyone help or suggest someone?

luvrbus · December 22, 2013, 02:38:29 PM

A Pro/Link ? what code is he flashing active codes are flashed via the stop engine light and inactive codes are flashed via the check engine light

opus · December 22, 2013, 03:12:18 PM

They think it started as a DDEC2, then they changed engines and they believe its a DDEC3 now. There are no lights on. They have a loss of power, almost like its starting in 2nd gear, which it isnt. They mentioned possibly turbo or is there a sensor related? Maybe an injector? They have tried all basic things, filters, etc

Sorry, I am the middle man and am a non-electric diesel guy.

luvrbus · December 22, 2013, 03:20:47 PM

It's probably just running on 1 bank he needs to check the fuses and power going to each side

opus · December 22, 2013, 03:24:54 PM

Wow, that would be quite noticeable, no? It scoots down the road fine, no smoke really...little vibration. Just doggy off the line.

luvrbus · December 22, 2013, 03:38:07 PM

Flashing the codes will give him the same results as a Pro/Link

opus · December 22, 2013, 03:49:48 PM

He has flashed codes, nothing active. With a Prolink couldnt he isolate cylinders to see if one in particular is a problem?

luvrbus · December 22, 2013, 03:55:45 PM

He can cut a injector out with the Pro/Link he can do that with a screw driver

opus · December 22, 2013, 04:22:13 PM

I told him to find an IR thermometer and give that a go first. That should give him an idea before he starts yanking off valve covers.

hargreaves · December 23, 2013, 07:33:08 AM

Check to make sure he has the correct turbo boost sensor for the engine. It is different on a DDEC 11 to a DDEC 111. If it goes into smoke control while accelerating it will seem sluggish until the bus gets going. Cheers Gerry

opus · December 23, 2013, 07:42:14 AM

I will relay this. I do believe this problem just started though. Everything had been fine.
I had suggested that if it acted like it was starting in 2nd gear to check and see that it wasnt....it wasnt.

luvrbus · December 23, 2013, 08:14:47 AM

I wonder if he changed the pulse wheel to the 36 tooth

Jon · December 23, 2013, 08:22:27 AM

Let me make this clear up front. I know nothing about DDEC.

But I do know if the coach was running OK and nobody screwed with it before it started exhibiting funny characteristics there are three things I would check. First would be the connectors. All connectors will tend to mess up the operation of a DDEC equipped engine if there is bad contacts or corrosion. Simply plugging or unplugging things a time or two makes a problem go away.

If that did not cure it I would verify the operation of the throttle position sensor and the operation of the turbo boost sensor, both of which I know can impact the engine power. Those have connectors also and would be on the list of ones to check.

opus · December 23, 2013, 08:26:15 AM

Gee....I surely dont know and he probably wouldnt know. All that is know is that it ran fine until recently. It still runs fine and they drive it. Its just the off the line power loss and a slight vibration at cruising speed.
I suggested Power Service because it had been sitting with a pretty empty tank for a couple months. I was thinking algea, water, bad fuel, etc.

I'm surely DDEC ignorant. In talking last night he mentioned "fixing" it once before by unplugging the main plug. He is going to try that again. I'm sure being in GA, that could be an issue.

B_K · December 23, 2013, 09:06:05 AM

I can tell you from personal experience that all of the above suggestions are good advice!

I have had the same experience with an 8V92 and the first time it turned out to be the fuses for the injectors.
One bank firing and one not. Sounded like it was running fine at idle. But a sick dog on take off. Once up to speed it did sorta OK but still not right. Changed fuse holders no more problems. Ran bus 3 more yrs and sold it!

Second experience was coming home from NC and in the mountains it was a complete dog. On the open highway it'd make do, but still struggled with any hill, or trying to acceleration at all.
And after pulling into a rest area to check it out w/no problems found it was a dog the rest of the way home.

After calling "The Don" he told me that he was pretty sure it was a bad boost sensor. Took the old one out, got the part # off it drove to Memphis and picked up a new one took it home, installed and test drove!

Problem solved!

Had the bad connections before too!

BK