2.4LH swap idle problem

[JW240]

on the back of the cluster there are two 6.3 mm pins, close to each other. Those give the speed signal.

http://www.hyperocity.com/volvo240/images/Volvo/odometerrepair/speedoback1.jpg

I think they are the ones left of the white block (back of speedo). There is a piece of hose around those connectors. I can't acces the external HD where i have the diagrams stored. pin 34 on the LH box is where the signal should go to.

 

[terrortore]

thnx a lot man,, i saw that "garden" hose showd over the two pins,, last time the odo was out to install two 170000mcd blue LED`s

just run a new wire, from #34 to any of the two pins?

 

[740Weapon]

VADIS on code 3-1-1

Condition

If the engine speed (RPM) is above 2100 rpm, the load signal is in the part-load range and the control module does not receive a signal from the speedometer for 8 seconds a diagnostic trouble code (DTC) is stored.


Possible source

-Open?circuit or short?circuit to ground in the cable from the combined instrument panel.
-Open?circuit or short?circuit to ground in cable between combined instrument panel and the sensor.


Fault symptom
-Idling problems.

under the diagnostics in VADIS it says that pin grounding causes the problem as does open line. and considering the logic behind the trouble code there appears to be no easy way out.

the ECU expects a "quadratic wave" between 1.5 Volts and battery voltage across pins 34 and 5. you could in theory make an emulator but this seems dumb to me.

-Dana

 

[Krisverde]

to get the speed signal it would be worth it to look where the old cruise control gets its signal. Even on my brothers 1982 760 there is a pin on the back of the cluster for the LH/cruise speed signal. Works perfect, just plugged it in.



speed-signal hooked up correctly?

I have a wire to the back of my cluster, just not sure what wire to put it to on the computer, how do you tell the pin #'s? I have it to a pink wire as I heard that's what controlled the 311 code.

 

[JW240]

I have a wire to the back of my cluster, just not sure what wire to put it to on the computer, how do you tell the pin #'s? I have it to a pink wire as I heard that's what controlled the 311 code.

pin 34 of LH.

thnx a lot man,, i saw that "garden" hose showd over the two pins,, last time the odo was out to install two 170000mcd blue LED`s

just run a new wire, from #34 to any of the two pins?

Yup, thats what we did on the 760.
My 1991 240 was prewired for it (just plugged in the newer comnputer and no error codes, saw a wire going to pin 34).

 

[malloy1]

There are several ways of getting the right pulse to Pin 34 as discussed here:

http://forums.turbobricks.com/showthread.php?t=132582&highlight=lh2*&page=2

I got a 12v square wave using a hall sensor/pullup circuit (top pictures the finished circuit setup and the bottom is the complete hall sensor/pull up circuit - The LED is to check that a pulse is being created) and using the drivshaft bolts as the targets (4 pulses per driveshaft revolution is pretty close to the 240 rearend):

The hall sensor:

This is what I got for the 9-pin plug next to the ECU (donor car was a 90 240):

Paul

 

[klr142]

Paul, do you have pictures of where you mounted the sensor and how it's working?

 

[malloy1]

Paul, do you have pictures of where you mounted the sensor and how it's working?

I built the circuit, tested on the driveshaft and got the right signal. I'm still working on my project and haven't got it to the point of running yet.

Plan to mount it on the flange of the OD here:

Paul

 

[meeki007]

this is a woderful thread. I'm in the middel of wiring up the lh2.4 into the volvo 145i and was wondering how i was going to fix this problem.

 

[klr142]

Ah, no wonder I hadn't seen anything yet. Thanks for that though, it shows where you'll be using it.

 

[meeki007]

I like this thinking We dont need a signal for the speedo and we only need a signal to pin 34 to be close to moving and not moving. I like this simplistic way of your thinking on this one Paul.

 

[volvofreak740]

There are several ways of getting the right pulse to Pin 34 as discussed here:

http://forums.turbobricks.com/showthread.php?t=132582&highlight=lh2*&page=2

I got a 12v square wave using a hall sensor/pullup circuit (top pictures the finished circuit setup and the bottom is the complete hall sensor/pull up circuit - The LED is to check that a pulse is being created) and using the drivshaft bolts as the targets (4 pulses per driveshaft revolution is pretty close to the 240 rearend):

The hall sensor:

This is what I got for the 9-pin plug next to the ECU (donor car was a 90 240):

Paul

yea thats only for 89 and 90 91 to 93 has a different connector but i thank u for posting it

 

[Group A]

Just an update:

We ended up putting a G80, diff cover with sensor and electronic speedo in the car and the idle problem is fixed.

 

[y-bot]

Just an update:

We ended up putting a G80, diff cover with sensor and electronic speedo in the car and the idle problem is fixed.

woo hoo!!!

 

[marcusicp]

Just an update:

We ended up putting a G80, diff cover with sensor and electronic speedo in the car and the idle problem is fixed.

What year did your electronic speedo come out of? What year and model rear diff cover and sensor did you use? What exactly is a "G80"? Is it a locker in the rear diff from Eaton? Thanks!

 

[blkaplan]

Just an update:

We ended up putting a G80, diff cover with sensor and electronic speedo in the car and the idle problem is fixed.

Funny thread to read through.
... the summary.... idle problem... Its the speedo!

no way a speedo problem could cause that!

ummmm maybe it is the speedo.

yea i guess that makes sense...

OP: it was the speedo.

 

[ZVOLV]

I drove around in my 1990 740 Turbo with the speedo pickup disconnected and it seemed OK, but I "think" I might have noticed a couple moments of high idle.

 

[Captain Bondo]

Funny thread to read through.
... the summary.... idle problem... Its the speedo!

no way a speedo problem could cause that!

ummmm maybe it is the speedo.

yea i guess that makes sense...

OP: it was the speedo.

Lol totally.

 

[A-Bro240]

What year did your electronic speedo come out of? What year and model rear diff cover and sensor did you use? What exactly is a "G80"? Is it a locker in the rear diff from Eaton? Thanks

!

G80 is locker, locker is a differential, differentials have speedo tone rings, speedo tone ring + sensor = speed signal, speed signal + computer (because some bosch goblins in sweden decided it does) = correct idle.

 

[Steve940Estate]

Hi
Haven't been on here in quite a while and spotted this thread and it got me thinking.
I've had a funny high idle problem on my car. Seemed to be caused by driving off in the car too soon after a cold start. This is cured by letting it sit idling for a while without touching the throttle. I have been through everything trying to cure this and the only thing I haven't looked at is the speedo signal to the ECU.
Reading through this makes me think that this might be the problem. It's something that has been bugging me since I did the engine swap on the car about 2 years ago !