Jump to content

Electronic Malfunction


Recommended Posts

Hey guys, new to this whole forum here but here goes nothing! I have a 1996 Mack CL 700 and recently I've been having a problem with it. When I first start the truck and drive a certain distance (seems to be the same distance every time) the electronic malfunction light comes on, and the truck loses a significant amount of power. I know this because I'm usually climbing a steep hill every time this happens, and it seems as tho the turbo loses all its boost. The light will then remain on and the truck will have little power, until it is shut off and left for a few minutes. Then it will reset. Any ideas about what this might be?

Link to comment
Share on other sites

Yeah I plan on bringing it to Mack, but that's not possible until sometime this coming summer (I live 6 hours from the nearest Mack dealer and I don't use the truck on the highway so). I heard about low coolant but couldn't see that as being the cause for loss of power. I'll look into it tho

Link to comment
Share on other sites

I lost my VSS once due to a loose yoke. I don't recall losing power. Does the speedo still work? Check for any codes next time it happens, as turckster said. It will flash a number of flashes, pause for a two seconds, then flash another number of flashes. (Electronic Malfunction Lamp) example, if it flashes once, then pauses two seconds, the flashes seven times, your code is a 1-7, which is related to a coolant sensor issue. Tell us what code you get, we can tell you what it means, or at least where to look.

Link to comment
Share on other sites

To find out what the fault is while it is active, push the set/resume switch up until the fault light goes out (cruise switch in the off position). It should flash on/off in two sets. That will help a lot in trying to figure out what is going on here.

^^^ this^^^

with cruise turned off, push the set/resume switch and count the flashes. this will give you the error code, and then you can determine what is wrong.

when you are up to your armpits in alligators,

it is hard to remember you only came in to drain the swamp..

Link to comment
Share on other sites

  • 11 months later...

I have a newer model CXU. The truck ran great without a load on it. The first time I tried pulling a loaded trailer the lightning bolt (MIL) came on and the truck derated and wouldn't go over 10 mph. I drove it straight to the dealer from there which was approx 12-15 miles away. It took me over 2 hours ! That was a painful ride and boy were the people behind me PO'ed ! Lol. Anyways after the dealer checked it out, it was leaking boost air pressure through some bad charge air cooler rubber connector hoses that join the hard pipes. I had a leak in the charge air cooler itself and a leak in the EGR pipe. They replaced everything except the charge air cooler and she pulled like a Mack is supposed to after that, even while still leaking some boost out of the CAC. When you take your CL up a hill, you're putting a load on it and that's when the turbo starts to boost. In my case, the dealer blocked the air intake system and then pressurizes with air to see if it holds or leaks. Mine is an 08, and if mine was worn/cracked, then yours with 12 more years of use and abuse might have a similar issue. I was almost certain my problem was electrical/sensor related. My truck is an autoshift too, so trans is electronically controlled and wouldn't shift passed 4th gear, but ended up being a completely mechanical failure. The one connector had rubbed through on the back side so it looked fine standing and looking at it. The dealer found it by following the air leaks. You could take yours apart and inspect them really good. Good luck buddy

 

Link to comment
Share on other sites

  • 5 years later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...