Speed Sensor and ECU Issues - Defender Source
Defender Source  

Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions


Reply
 
Thread Tools
  #1  
Old July 22nd, 2005, 03:46 PM
DJ Menasco's Avatar
DJ Menasco
Status: Offline
DJ Menasco
#500/500
Member
 
Join Date: Sep 2003
Location: Oregon/South Carolina
Posts: 920
Speed Sensor and ECU Issues

Gang

I've got a problem with my "Check Engine Light." It won't turn off. The code display throws Code 48 - Stepper motor" so I changed the stepper and followed the reset instructions, however, the lamp turns back on. Unfortunately code 48 also recommends that I check the road speed sensor. Since I no longer possess and OEM speedo setup I'm thinking the ECU is not recieving a signal from the sensor. While I've combed the FAQ I couldn't find any recommendations on this particular issue. Other than removing the bulb does anyone have any ideas how I might deceive the ECU into thinking the sensor is operational? I'd like to retain the use of the ECU code reader should other issues arrise.

Thanks.

DJ
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old July 22nd, 2005, 04:17 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
The speed sensor should be down by the transfer case, not up in the dash. Did you take it out when you changed the speedo?

Also, you might want to check your base idle speed. If the RPM is outside of the accepted range, it will also trigger the light. The computer uses the stepper motor to raise it up, but you may have to manually adjust it down too.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #3  
Old July 22nd, 2005, 04:29 PM
DJ Menasco's Avatar
DJ Menasco
Status: Offline
DJ Menasco
#500/500
Member
 
Join Date: Sep 2003
Location: Oregon/South Carolina
Posts: 920
Exclamation

Quote:
Originally Posted by Hans
The speed sensor should be down by the transfer case, not up in the dash. Did you take it out when you changed the speedo?
I removed the transducer, but that's it. I has a speedo shop install the a new hall sensor that was compatable with my VDO speedo.

Quote:
Also, you might want to check your base idle speed. If the RPM is outside of the accepted range, it will also trigger the light. The computer uses the stepper motor to raise it up, but you may have to manually adjust it down too.
Hmm, good idea. I didn't think to test to see if the tachometer is functioning properly. Is this something that would require a specific diagnostic instrument or can I use a volt meter on the alternator? As for the stepper, how do I adjust it manually?

Thansk Hans.

DJ
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old July 22nd, 2005, 05:15 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
Normally, you can just go by the tach itself, that should suffice. But if it's reading more than 50rpm off from 700.... it's out of whack. The manual adjustment is done by removing a small plug next to the throttle body, which uncovers the adjustment screw.

So yours had the electonic speedo? Hmmm, I wonder if that uses the same transducer for both the speedometer and the ECU. And just to make sure I'm spouting the right info, Distributor or No Distributor?

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #5  
Old July 24th, 2005, 02:56 PM
DJ Menasco's Avatar
DJ Menasco
Status: Offline
DJ Menasco
#500/500
Member
 
Join Date: Sep 2003
Location: Oregon/South Carolina
Posts: 920
Quote:
Originally Posted by Hans
Normally, you can just go by the tach itself, that should suffice. But if it's reading more than 50rpm off from 700.... it's out of whack. The manual adjustment is done by removing a small plug next to the throttle body, which uncovers the adjustment screw.
Ok, thanks Hans.

Quote:
So yours had the electonic speedo? Hmmm, I wonder if that uses the same transducer for both the speedometer and the ECU. And just to make sure I'm spouting the right info, Distributor or No Distributor?

-Hans

Nope, my D90 is a 95 and thus had the mechanical speedo and uses a distributor. I swapped the OEM speedot out for an electronic module.


DJ
Reply With Quote
  #6  
Old July 24th, 2005, 03:24 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
Hmmmmm, maybe I need to crawl underneath mine tomorrow and see exactly how that thing is set up. Without the speed sensor down there, you're probably going to keep getting the light.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #7  
Old July 24th, 2005, 04:18 PM
DJ Menasco's Avatar
DJ Menasco
Status: Offline
DJ Menasco
#500/500
Member
 
Join Date: Sep 2003
Location: Oregon/South Carolina
Posts: 920
Quote:
Originally Posted by Hans
Hmmmmm, maybe I need to crawl underneath mine tomorrow and see exactly how that thing is set up. Without the speed sensor down there, you're probably going to keep getting the light.

-Hans

That's what I was curious about. Does the transducer house the speed sensor?

DJ
Reply With Quote
  #8  
Old July 24th, 2005, 06:18 PM
Mike Hippert's Avatar
Mike Hippert
Status: Offline
D-90Slut/Stalker,SNLPres
94 D-90 Grinding Rover
Member
 
Join Date: Sep 2003
Location: Manchester NH USA
Posts: 4,789
Yes, what happens is as soon as the vehical goes into motion the ECU changes the settings to a few things (Like the stepper). Jimmy has the same problem as his lower speedo cable doesn't work. I know a few people have done something to send a signal to the ECU so that this isn't a problem but I don't know what exactly they did, weather it was put the sensor back inline or use the signal from the new speed sensor.
__________________
Don't forget to
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
first then ask questions later! The loose nut behind the wheel
Reply With Quote
  #9  
Old February 15th, 2006, 01:50 PM
Heath's Avatar
Heath
Status: Offline
Heath Ahrens
1995/D-90
Member
 
Join Date: Feb 2004
Location: Bernardsville, NJ, US
Posts: 125
Hmm... I wonder if I am having a similar problem here?
I'm getting code 68. Allong with a surging idle and general lack of power.
The idle drops low sometimes, especially when coming to a stop.
I was getting a code 44 for a little while. But it seems to have been replaced by the code 68.
I wish I could search for numbers in this forum.
Reply With Quote
  #10  
Old February 15th, 2006, 02:39 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
The codes are in the FAQ, up in the top header, in the ECU/Computer section.

Code 68 is 'Road Speed Sensor' and the symptoms describe that as well. Part of it's function is to keep the idle speed a bit higher when you are moving, to prevent stalling when you are rolling to a stop.

Code 44 is the left side O2 sensor.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #11  
Old February 15th, 2006, 05:35 PM
Heath's Avatar
Heath
Status: Offline
Heath Ahrens
1995/D-90
Member
 
Join Date: Feb 2004
Location: Bernardsville, NJ, US
Posts: 125
Ok.
Thanks Hans.
Now would the part that is bad be possibly the unit where the spedo cable meets the cable from the t-case with the green and yellow wires (is this aka the transducer?? Or the part that is in the transfer case (which I don't know the name of).
Or both?
I wonder if the code 44 was coming from the almost failed road speed sensor?

Thanks,
Heath
Reply With Quote
  #12  
Old February 15th, 2006, 07:08 PM
Hans's Avatar
Hans
Status: Offline
Hans Haase
The D-90.com Lab Rat
Member
 
Join Date: Oct 2003
Location: Long Island, NY
Posts: 2,381
Yes, the box with the wires down by the T-case is what you're dealing with. Thats the VSS.

The Code 44 might have been caused by the computer getting some wacky signals from the speed sensor, if it doesn't come back I wouldn't worry about it just yet.

-Hans
__________________
My oil line fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
My 100k stopped odometer fix

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.
Reply With Quote
  #13  
Old February 15th, 2006, 09:01 PM
Heath's Avatar
Heath
Status: Offline
Heath Ahrens
1995/D-90
Member
 
Join Date: Feb 2004
Location: Bernardsville, NJ, US
Posts: 125
It comes back every day now (code 68). After about 25 or so miles.
I am more concerned with the general lack of power.
I was driving my 1996 FJZ80 Landcruiser (with 205K miles) yesterday and it's 225 HP seemed much more powerful than my Stage 1 4.6L RPI V8 complete with Tornado chip, the most overpriced chip in the world. I feel like I'm taking crazy pills.
It just takes to long too rev up. It has no balls. I feel like it is just marginally better than the 3.9.
I wonder if the timing marks are off and it is running too advanced or retarded.
I just don't know anymore.
I pulled the plugs yesterday and they looked ok, a little bit of whiteish ash on them but nothing crazy.
Sometimes a little bit of watery black soot comes out of the exhaust when I start up.
Could I be destroying my engine without knowing it?
I check the oil frequently.
Yes I am paranoid.
I can't afford not to be.
Thanks for the help.
Reply With Quote
  #14  
Old February 16th, 2006, 02:50 PM
Doug's Avatar
Doug
Status: Offline
Doug Walker
TVR5L-powered NAS D-110
Member
 
Join Date: Oct 2003
Location: Los Angeles, CA, USA
Posts: 880
'long time to rev up' is a big key here. Fuel and/or air starvation, imho. Sounds like the plugs are saying you are running lean, which indicates fuel starvation. Fuel filter, fuel pump? Check the fuel pressure is close to 40. See what happens to it when you rev it up.

Get a timing light. Easiest thing in the world to use.

My thoughts.

Doug W.
Reply With Quote
  #15  
Old February 16th, 2006, 08:45 PM
Heath's Avatar
Heath
Status: Offline
Heath Ahrens
1995/D-90
Member
 
Join Date: Feb 2004
Location: Bernardsville, NJ, US
Posts: 125
The timing light says it is at 6 deg before TDC
I'm just not sure the timing marks are right.
It revs up fine when there is no load.
I must have made that unclear.
The engine just doesn't have enough power.

I need to get some sort of tool to check the fuel pressure.
Is there a special Land Rover tool?
That could be it. I hope it is not the pump!!!
If it is just off a few psi... could that be the problem.
I will change the fuel filter this weekend.

I have to finish puting in the front air locker in the morning.
Man that third member had a crap load of rtv on it and too much locktite on everything else(it was replaced under extended warantee by LR in 1999 and they punished me by over torquing everything).
Reply With Quote
Reply

Lower Navigation
Go Back   Defender Source > Defender & Series Technical Discussions > Defender Technical Discussions

Tags
ecu, sensor

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Defender Registry

Blu

Cred

Kickler

Kickler
Add your Defender

All times are GMT -5. The time now is 08:12 PM.


Copyright