'94 P30 6.5TD Codes: 27 & 49

[Allamanda]

Hi All,

Driving along, sudden drop in power (feels like the turbo waste gate has opened) SES light on. Put into N turn off and restart, clears and all is well. Seems to esp do this if I work her hard under load, up a steep hill for example.

The chassis is the underpinning for a Winnebago Brave 27 and most times we have a Toyota Yaris hanging off the back. Although an Oct '94, has only just cleared 36,000 miles.

Other fault I have noted, but not got round to looking in to properly yet, is the charge voltage is all over the place, seems worse at higher RPM. Checked ripple, which is good, so suspect: faulty connection somewhere, voltage reg giving up, slip ring out of shape causing brush bounce.

Read the codes tonight and I am getting 27 & 49. Cleared them ok and they haven't come straight back after a short run.

I am a vehicle tech so know what's what (most of the time ), but haven't got my head round all of your abbreviations yet, so be kind if I ask what to you seems a dumb question or two. I have read lots of advise on earth problems, so will check those this weekend, although I have already volt dropped the main cables, which all check out ok.

So, my US friends, before I dive in, alternator problems causing spurious codes?? Or are 27 & 49 common on these?? What are the likely culprits for these codes? All advice welcome, I am a Chevy virgin so starting my knowledge from scratch. Needless to say, I'd rather be spending my time in the Winnie relaxing rather than under the hood so any time savings will be gratefully received.

Thanks in advance guys,

Alan (spanner turner) & Amanda (coffee maker to spanner turner )

 

[Slim Shady]

Hi All,

Driving along, sudden drop in power (feels like the turbo waste gate has opened) SES light on. Put into N turn off and restart, clears and all is well. Seems to esp do this if I work her hard under load, up a steep hill for example.

The chassis is the underpinning for a Winnebago Brave 27 and most times we have a Toyota Yaris hanging off the back. Although an Oct '94, has only just cleared 36,000 miles.

Other fault I have noted, but not got round to looking in to properly yet, is the charge voltage is all over the place, seems worse at higher RPM. Checked ripple, which is good, so suspect: faulty connection somewhere, voltage reg giving up, slip ring out of shape causing brush bounce.

Read the codes tonight and I am getting 27 & 49. Cleared them ok and they haven't come straight back after a short run.

I am a vehicle tech so know what's what (most of the time ), but haven't got my head round all of your abbreviations yet, so be kind if I ask what to you seems a dumb question or two. I have read lots of advise on earth problems, so will check those this weekend, although I have already volt dropped the main cables, which all check out ok.

So, my US friends, before I dive in, alternator problems causing spurious codes?? Or are 27 & 49 common on these?? What are the likely culprits for these codes? All advice welcome, I am a Chevy virgin so starting my knowledge from scratch. Needless to say, I'd rather be spending my time in the Winnie relaxing rather than under the hood so any time savings will be gratefully received.

Thanks in advance guys,

Alan (spanner turner) & Amanda (coffee maker to spanner turner )

First and foremost welcome to the truckstop.

Code 27 is an accelerator pedal circuit #2 position fault. states that with only one circuit out pedal should work normal and no service engine light.

Code 49 is Service Throttle soon light, an open in the service throttle soon light circuit can cause this. or a faulty bulb.

Hope this helps some. Your de-fueling is because of intake air temps on that large a chassis. The turbo is running at boost and intake air temps rise above 270 Fahrenheit causing a defuel to save your engine. I have a solution and the one guy that did his ended up going from 7 to 9 mpg towing his 20 foot race trailer behind the same combo you have.