Correct. The high idle problem when not running a VSS occurs after a higher rpm pull. It may or may not be related to load. It may just be that the ECM expects the vehicle speed to register something if the engine rpm is ever that high? I can?t say for certain.
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LH 2.4 swap idle issue
- Thread starter paulcurran
- Start date
smoothdurban
I do my own stunts
- Joined
- Jan 4, 2013
- Location
- Kemble Ontario
I am hoping to install the board on monday.
My engine runs and idles flawlessly without the VSS. Again less then 200 miles on a rebuilt engine so I am not running any long highway runs or 12+ psi of boost. Mine is a MANual!
My engine runs and idles flawlessly without the VSS. Again less then 200 miles on a rebuilt engine so I am not running any long highway runs or 12+ psi of boost. Mine is a MANual!
smoothdurban
I do my own stunts
- Joined
- Jan 4, 2013
- Location
- Kemble Ontario
Ok I couldn't wait so I installed it an it definitely has an effect on idle. First off my throttle body has an Idle adjustment screw. Originally I had this screw adjusted such that it was completely closed and without this hack installed it seemed to idle fine in all conditions.
After installing the board provided to my by bob right off the bat the idle was low, almost to the point of stall. I adjusted the idle screw open a few turns and it runs like a champ. By far more adaptive then it was before.
What was the correct procedure to set idle again? Disconnect the IAC and the set base to 500?
Perhaps this is just me but it seems to accelerate a little better too.
Bob I did verify that the light you sent with my board is flashing and you're instructions were superb!
I cannot check for codes as my code reader has a couple breaks in that jumper wire perhaps I can rig something up tomorrow or put in a request for a good used one in the wanted section or borrow the one from my 245!!
Its late here so I haven't had a chance to go to the highway yet but I plan on trying it tomorrow.
After installing the board provided to my by bob right off the bat the idle was low, almost to the point of stall. I adjusted the idle screw open a few turns and it runs like a champ. By far more adaptive then it was before.
What was the correct procedure to set idle again? Disconnect the IAC and the set base to 500?
Perhaps this is just me but it seems to accelerate a little better too.
Bob I did verify that the light you sent with my board is flashing and you're instructions were superb!
I cannot check for codes as my code reader has a couple breaks in that jumper wire perhaps I can rig something up tomorrow or put in a request for a good used one in the wanted section or borrow the one from my 245!!
Its late here so I haven't had a chance to go to the highway yet but I plan on trying it tomorrow.
smoothdurban
I do my own stunts
- Joined
- Jan 4, 2013
- Location
- Kemble Ontario
Just another update.
I got this dialed in and it works flawlessly.
Thanks again bob for your help. I highly recommend this is the way to go if you want to supply VSS to your ECU.
Cheers! now make some more!
I got this dialed in and it works flawlessly.
Thanks again bob for your help. I highly recommend this is the way to go if you want to supply VSS to your ECU.
Cheers! now make some more!
Last edited:
obie1luv
Member
- Joined
- Feb 16, 2014
- Location
- chandler, az
I could also use one of those handy dandy vss cheater boards... how much?
Yes, but it's even better if you set it to 750rpm(or higher if you have a large camshaft).
oldschoolvolvo
Well-known member
- Joined
- Mar 27, 2004
- Location
- Lancaster, PA
@bobxyz...nice work
-do you know if all early cable speedos have the provisions for cruise control output?
-would the output from a Ford T5 VSS work as an input to the "cheater board", provided the T5 speedo gearing is ~accurate?
*Edit: Canuck says Ford VSS cannot be used to drive a LH2.4 speedo/ECU. However a Ford VSS + Dakota Digital speedo unit WILL work.
https://forums.tbforums.com/showpost.php?p=4988923&postcount=12
I also checked my '79 cluster and it does not have the cruise output terminals, so YMMV on that one I guess
.
-do you know if all early cable speedos have the provisions for cruise control output?
-would the output from a Ford T5 VSS work as an input to the "cheater board", provided the T5 speedo gearing is ~accurate?
*Edit: Canuck says Ford VSS cannot be used to drive a LH2.4 speedo/ECU. However a Ford VSS + Dakota Digital speedo unit WILL work.
https://forums.tbforums.com/showpost.php?p=4988923&postcount=12
I also checked my '79 cluster and it does not have the cruise output terminals, so YMMV on that one I guess
.
Last edited:
Harry Tuttle
Well-known member
- Joined
- Jun 2, 2006
- Location
- in your ducts
I believe that the only year that the early style speedo had this cruise interface was '80, as the earlier cars used a different type of cruise control.
bobxyz
Board Member
- Joined
- Aug 29, 2014
- Location
- Boulder CO
Other Options for Generating LH2.4 VSS
I've been running my LH2.4 converted '85 245 GLT using the mecanical speedo cruise control sensor and a gutted electronic speedometer board for a couple years now. It still works fine, but I never figured out exactly what LH2.4 uses the VSS signal for, other than generating a CEL and high idle when VSS is missing. The only other install like this that I know of is smoothdurban's, and I think his is working fine too.
Since the original post, 240's in the local salvage yards have mostly dried up. The days of finding a $7 electronic speedo to gut are gone. Based on some offline inquiries, I thought about VSS generation and some other possible options. I haven't tried any of these, but I think they're promising.
Options for generating VSS on early 240s:
1) change to later rear differential and swap to cluster with electronic speedometer
2) use speedo cruise pickup with gutted electronic speedo board - see previous posts.
3) use speedo cruise pickup with MegaSquirt VR conditioner board.
4) use speedo cruise pickup with aftermarket speedo adapter box.
5) use GPS speedo sensor
6) add a custom bracket with a sensor for the driveshaft bolts or add-on flags
7) add an inline speedo cable sensor
Background:
The LH2.4 ECU needs a VSS vehicle speed sensor signal so that idle doesn't misbehave. The factory signal is generated from a VR sensor on the rear differential cover (either 12 or 48 pulses per axle rev), and is conditioned by the circuit board on the back of the electronic speedometer. Pre-ABS cars (K9800 or K10042 speedos) pass the conditioned VR signal directly to the ECU. ABS cars (K39200 or K40168 speedos) divide the 48 pulse VR sensor by 4 to generate VSS. So, the factory LH2.4 VSS signal is about 10,000 pulses per mile.
The K9800 number on the electronic speedos is the calibration number, in pulse per mile. For example, a 205/60R15 tire gets 817 revs/mile. Multiply this by the differential pulses per axle rev (12 or 48 ABS), and you get the K number: 817 * 12 = 9804.
Old cable driven speedometers are often calibrated for 1000 cable revs per mile. The 240 cable speedos have a slightly different calibration - the r0,960 speedos are 0.960 miles/1000 revs, and the r0,980 speedos are 0.980 miles/1000 revs. Within the cable speedos is a 4-tooth wheel for cruise control. This gives a little over 4000 pulses per mile with the cruise control VR pickup.
VSS Option 1 - change to later rear differential and swap to cluster with electronic speedometer
The most straightforward way of generating a proper LH2.4 VSS signal is to swap to a LH2.4 differential with a 12 or 24 tooth VSS VR sensor, and swap to the matching cluster or electronic speedo. With this, VSS is available on the electronic speedo board or, if swapping clusters, on the double 1/4" spade connector just to the left of the speedo. I haven't swapped these dash components, so I don't know what rewiring or mechanical fitting is needed. Note: if you already have a LH2.2 with an electronic speedometer, the VSS signal is already available on the back of the cluster.
VSS Options 2,3,4 Speedo Cruise Control Pickup
The 1981-1985 speedometers all have provisions on the back to add a VR sensor for cruise control. I think the 1980 version of the earlier style cluster also has the option to add a cruise control sensor to the back of the speedo, but I haven't seen one personally.
It's easy to spot the cruise control pickup in most any picture of the back of a cluster. Flipping through the current ebay ads, it looks like the cruise control pickup is only installed on ~10% of the clusters. I think it's a much more common option with the factory turbo cars -- they were top of the line when they came out, and the original owners would be more likely to add factory cruise control.
VSS Option 3 - speedo cruise pickup with MegaSquirt VR conditioner board
Instead of modifying the PCB from an electronic speedo, it should be possible to use a VR sensor conditioner board from MegaSquirt to generate the VSS signal. For example, the below board should work, and has a version that runs off of 12volts. You'll need to add a 10K resistor and a 2N3904 transistor to convert to open collector (the LH2.4 ECU includes its own 10K pullup to +12v). You'd wire up ground to GND, switched +12v to +V, VR cruise pickup to VR1+ and VR1- (polarity doesn't matter), and Out1 to resistor to transistor to LH2.4 VSS.
http://jbperf.com/dual_VR/v2_1.html
I think that the gutted speedo board may be a little more sensitive to the VR signal than the MegaSquirt board. This would only show up at low speeds with small VR sensor voltages (e.g. ~200mv pk-pk at 5mph). I don't think the LH2.4 ECU would care, but I haven't tried this option myself.
VSS Option 4 - speedo cruise pickup with aftermarket adapter box
I haven't tried these, but I think that either one can connect directly to the speedo cruise VR sensor pickup and generate VSS directly. It may take some work to figure out how to best calibrate these boxes. It should be possible to generate a VSS signal close to the factory LH2.4 10,000 pulses/mile rate using the ~4000 pulses/mile rate from the speedo cruise sensor. (If calibration is difficult, the standard 8000 ppm rate should be OK.)
https://shop.classicinstruments.com/sn74z
https://www.dakotadigital.com/index...id=1192/category_id=287/mode=prod/prd1192.htm
VSS Option 5 - GPS Speedometer Sensor
It may be possible to connect a GPS Speedometer Sensor directly to the LH2.4 VSS signal. This would certainly be simple and clean, but I have some concerns. First off, the VSS calibration value for the sensor may not work well with the expected 10,000 pules/mile LH2.4 rate. Standard GPS VSS rates are 8000 or 16000 pulses/mile. I'd expect 8000 to work, but 16000 may be too fast.
My second concern is the GPS behavior when first powered up, or when signal is lost (e.g. tunnel or canyon). If the GPS sensor is powered at all times, it will maintain satellite lock and should generate a good VSS signal almost immediately. If the GPS sensor is turned off, it may take minutes{?} to acquire satellite lock and generate a good VSS signal. I think that some GPS sensors include a small backup battery. This is OK, but may not last very long over Colorado's -5deg to 100+ deg temperatures.
My last concern is the vehicle speed update rate - if you coast to a stop, it may take too long for the GPS sensor to detect this and drop the VSS signal rate. I don't know how tolerant the LH2.4 ECU would be to this case.
A couple GPS sensor candidates are:
amazon: "IIL GPS Speed Sensor/Sender" - this one is cheap, $45, but uses a higher 16,000 pulses/sec calibration, and may have a slow update rate.
amazon: "GlowShift GPS Speedometer Sensor Adapter Kit" - this one is $90, and based on comments, uses 8000 pulses/sec calibration.
VSS Option 6 - custom bracket with a sensor for the driveshaft bolts or add-on flags
Add a custom bracket with a 3-wire hall sensor, or a 2-wire VR sensor plus conditioner board/box, to sense the 4 driveshaft bolts or add-on flags. This would give 4* differential ratio pulses per axle rev, e.g. 3.73*4 = 14.9, versus factory LH2.4 12 pulses per axle rev. See:
http://forums.turbobricks.com/showthread.php?t=191751
http://forums.turbobricks.com/showthread.php?t=132582
https://www.digikey.com/htmldatasheets/production/57408/0/0/1/gs1005-gs1007-series.html (or see tooth sensors at diyautotune.com)
VSS Option 7 - add an inline speedo cable sensor
I've seen some VSS adapters for old American cars that splice into the middle of the mechanical speedo cable. Ideally, you'd like a 3-wire Hall Sensor adapter that generates 8000 pulses per mile. This would connect directly to the LH2.4 ECU without needing a VR conditioner board/box.
Has anyone else generated a VSS signal for LH2.4? If so, how did you do it and how did it work out?
-Bob
I've been running my LH2.4 converted '85 245 GLT using the mecanical speedo cruise control sensor and a gutted electronic speedometer board for a couple years now. It still works fine, but I never figured out exactly what LH2.4 uses the VSS signal for, other than generating a CEL and high idle when VSS is missing. The only other install like this that I know of is smoothdurban's, and I think his is working fine too.
Since the original post, 240's in the local salvage yards have mostly dried up. The days of finding a $7 electronic speedo to gut are gone. Based on some offline inquiries, I thought about VSS generation and some other possible options. I haven't tried any of these, but I think they're promising.
Options for generating VSS on early 240s:
1) change to later rear differential and swap to cluster with electronic speedometer
2) use speedo cruise pickup with gutted electronic speedo board - see previous posts.
3) use speedo cruise pickup with MegaSquirt VR conditioner board.
4) use speedo cruise pickup with aftermarket speedo adapter box.
5) use GPS speedo sensor
6) add a custom bracket with a sensor for the driveshaft bolts or add-on flags
7) add an inline speedo cable sensor
Background:
The LH2.4 ECU needs a VSS vehicle speed sensor signal so that idle doesn't misbehave. The factory signal is generated from a VR sensor on the rear differential cover (either 12 or 48 pulses per axle rev), and is conditioned by the circuit board on the back of the electronic speedometer. Pre-ABS cars (K9800 or K10042 speedos) pass the conditioned VR signal directly to the ECU. ABS cars (K39200 or K40168 speedos) divide the 48 pulse VR sensor by 4 to generate VSS. So, the factory LH2.4 VSS signal is about 10,000 pulses per mile.
The K9800 number on the electronic speedos is the calibration number, in pulse per mile. For example, a 205/60R15 tire gets 817 revs/mile. Multiply this by the differential pulses per axle rev (12 or 48 ABS), and you get the K number: 817 * 12 = 9804.
Old cable driven speedometers are often calibrated for 1000 cable revs per mile. The 240 cable speedos have a slightly different calibration - the r0,960 speedos are 0.960 miles/1000 revs, and the r0,980 speedos are 0.980 miles/1000 revs. Within the cable speedos is a 4-tooth wheel for cruise control. This gives a little over 4000 pulses per mile with the cruise control VR pickup.
VSS Option 1 - change to later rear differential and swap to cluster with electronic speedometer
The most straightforward way of generating a proper LH2.4 VSS signal is to swap to a LH2.4 differential with a 12 or 24 tooth VSS VR sensor, and swap to the matching cluster or electronic speedo. With this, VSS is available on the electronic speedo board or, if swapping clusters, on the double 1/4" spade connector just to the left of the speedo. I haven't swapped these dash components, so I don't know what rewiring or mechanical fitting is needed. Note: if you already have a LH2.2 with an electronic speedometer, the VSS signal is already available on the back of the cluster.
VSS Options 2,3,4 Speedo Cruise Control Pickup
The 1981-1985 speedometers all have provisions on the back to add a VR sensor for cruise control. I think the 1980 version of the earlier style cluster also has the option to add a cruise control sensor to the back of the speedo, but I haven't seen one personally.
It's easy to spot the cruise control pickup in most any picture of the back of a cluster. Flipping through the current ebay ads, it looks like the cruise control pickup is only installed on ~10% of the clusters. I think it's a much more common option with the factory turbo cars -- they were top of the line when they came out, and the original owners would be more likely to add factory cruise control.
VSS Option 3 - speedo cruise pickup with MegaSquirt VR conditioner board
Instead of modifying the PCB from an electronic speedo, it should be possible to use a VR sensor conditioner board from MegaSquirt to generate the VSS signal. For example, the below board should work, and has a version that runs off of 12volts. You'll need to add a 10K resistor and a 2N3904 transistor to convert to open collector (the LH2.4 ECU includes its own 10K pullup to +12v). You'd wire up ground to GND, switched +12v to +V, VR cruise pickup to VR1+ and VR1- (polarity doesn't matter), and Out1 to resistor to transistor to LH2.4 VSS.
http://jbperf.com/dual_VR/v2_1.html
I think that the gutted speedo board may be a little more sensitive to the VR signal than the MegaSquirt board. This would only show up at low speeds with small VR sensor voltages (e.g. ~200mv pk-pk at 5mph). I don't think the LH2.4 ECU would care, but I haven't tried this option myself.
VSS Option 4 - speedo cruise pickup with aftermarket adapter box
I haven't tried these, but I think that either one can connect directly to the speedo cruise VR sensor pickup and generate VSS directly. It may take some work to figure out how to best calibrate these boxes. It should be possible to generate a VSS signal close to the factory LH2.4 10,000 pulses/mile rate using the ~4000 pulses/mile rate from the speedo cruise sensor. (If calibration is difficult, the standard 8000 ppm rate should be OK.)
https://shop.classicinstruments.com/sn74z
https://www.dakotadigital.com/index...id=1192/category_id=287/mode=prod/prd1192.htm
VSS Option 5 - GPS Speedometer Sensor
It may be possible to connect a GPS Speedometer Sensor directly to the LH2.4 VSS signal. This would certainly be simple and clean, but I have some concerns. First off, the VSS calibration value for the sensor may not work well with the expected 10,000 pules/mile LH2.4 rate. Standard GPS VSS rates are 8000 or 16000 pulses/mile. I'd expect 8000 to work, but 16000 may be too fast.
My second concern is the GPS behavior when first powered up, or when signal is lost (e.g. tunnel or canyon). If the GPS sensor is powered at all times, it will maintain satellite lock and should generate a good VSS signal almost immediately. If the GPS sensor is turned off, it may take minutes{?} to acquire satellite lock and generate a good VSS signal. I think that some GPS sensors include a small backup battery. This is OK, but may not last very long over Colorado's -5deg to 100+ deg temperatures.
My last concern is the vehicle speed update rate - if you coast to a stop, it may take too long for the GPS sensor to detect this and drop the VSS signal rate. I don't know how tolerant the LH2.4 ECU would be to this case.
A couple GPS sensor candidates are:
amazon: "IIL GPS Speed Sensor/Sender" - this one is cheap, $45, but uses a higher 16,000 pulses/sec calibration, and may have a slow update rate.
amazon: "GlowShift GPS Speedometer Sensor Adapter Kit" - this one is $90, and based on comments, uses 8000 pulses/sec calibration.
VSS Option 6 - custom bracket with a sensor for the driveshaft bolts or add-on flags
Add a custom bracket with a 3-wire hall sensor, or a 2-wire VR sensor plus conditioner board/box, to sense the 4 driveshaft bolts or add-on flags. This would give 4* differential ratio pulses per axle rev, e.g. 3.73*4 = 14.9, versus factory LH2.4 12 pulses per axle rev. See:
http://forums.turbobricks.com/showthread.php?t=191751
http://forums.turbobricks.com/showthread.php?t=132582
https://www.digikey.com/htmldatasheets/production/57408/0/0/1/gs1005-gs1007-series.html (or see tooth sensors at diyautotune.com)
VSS Option 7 - add an inline speedo cable sensor
I've seen some VSS adapters for old American cars that splice into the middle of the mechanical speedo cable. Ideally, you'd like a 3-wire Hall Sensor adapter that generates 8000 pulses per mile. This would connect directly to the LH2.4 ECU without needing a VR conditioner board/box.
Has anyone else generated a VSS signal for LH2.4? If so, how did you do it and how did it work out?
-Bob
Last edited:
Electronic Dash Auto vs. manual
Any idea if the dash cluster from an auto equipped car will work just fine on a manual. Local P&P has a couple 90-92 240's, both are auto. I want to upgrade my 83 244 which is a manual, and was considering just doing LH2.2 because I didn't want to deal with the VSS and crank position sensor issues that LH2.4 brings up with a swap. From what I am reading, if I can pull the rear end(that already has the tone ring in the differential), and the dash from an auto equipped car along with all associated computers and sensors, I can upgrade all the way to LH2.4 assuming I also make provisions for CPS.
Or am I making it to complicated? Is it less work to use this work around on my current dash? I'm an ok shade tree mechanic. I can unbolt stuff and put it back on. I can figure out basic diagnostic stuff and don't mind learning. I just don't want to have one of those projects that dies because I bit off more than I can chew.
Any idea if the dash cluster from an auto equipped car will work just fine on a manual. Local P&P has a couple 90-92 240's, both are auto. I want to upgrade my 83 244 which is a manual, and was considering just doing LH2.2 because I didn't want to deal with the VSS and crank position sensor issues that LH2.4 brings up with a swap. From what I am reading, if I can pull the rear end(that already has the tone ring in the differential), and the dash from an auto equipped car along with all associated computers and sensors, I can upgrade all the way to LH2.4 assuming I also make provisions for CPS.
Or am I making it to complicated? Is it less work to use this work around on my current dash? I'm an ok shade tree mechanic. I can unbolt stuff and put it back on. I can figure out basic diagnostic stuff and don't mind learning. I just don't want to have one of those projects that dies because I bit off more than I can chew.
bgpzfm142
crossmember
- Joined
- Dec 25, 2013
- Location
- Launceston, Tasmana
Option (7): adding an inline speedo cable sensor
An old thread awakes!
Part of that problem has been solved. The hard part was finding a suitable sender which was available off the shelf that would fit a Volvo-type gearbox fitting.
Following at suggestion from timbo on Oz Volvo, I've just got a hold of a Brantz BR4 sensor, which connects straight up to a M40 / M41 / M45 / M46 / early AW7x speedo connection at the gearbox.
This device has a suitable female M18 x 1.5mm thread for attaching to the gearbox ferrule, and a male thread on the other side for attaching the speedo cable.
Here t'is, attached to an M46 ferrule.
It provides 4 pulses per revolution with a 200mA sink capacity and requires a 5v to 13v power supply. For the pulse conditioner (and in order to get the required 8,000 pulses per mile) I'll add a home-brew circuit incorporating a Schmitt trigger and pulse multiplier, fashioned out of couple of 7400-series ICs. Thanks to cleanflametrap's research on the signals generated by a genuine LH2.4 speedometer, it should be pretty easy to get the circuit to get the correct pulse shapes that will make the ECU happy.
These BR4 units will come in very handy for folks wanting to put LH 2.4 into their pre-81 240s and retaining the original speedo cluster, and who don't want to go through the tedious process of changing the rear axle.
Available here:
https://www.brantz.co.uk/product-page/european-gearbox-sensor-br4
An old thread awakes!
Part of that problem has been solved. The hard part was finding a suitable sender which was available off the shelf that would fit a Volvo-type gearbox fitting.
Following at suggestion from timbo on Oz Volvo, I've just got a hold of a Brantz BR4 sensor, which connects straight up to a M40 / M41 / M45 / M46 / early AW7x speedo connection at the gearbox.
This device has a suitable female M18 x 1.5mm thread for attaching to the gearbox ferrule, and a male thread on the other side for attaching the speedo cable.
Here t'is, attached to an M46 ferrule.
It provides 4 pulses per revolution with a 200mA sink capacity and requires a 5v to 13v power supply. For the pulse conditioner (and in order to get the required 8,000 pulses per mile) I'll add a home-brew circuit incorporating a Schmitt trigger and pulse multiplier, fashioned out of couple of 7400-series ICs. Thanks to cleanflametrap's research on the signals generated by a genuine LH2.4 speedometer, it should be pretty easy to get the circuit to get the correct pulse shapes that will make the ECU happy.
These BR4 units will come in very handy for folks wanting to put LH 2.4 into their pre-81 240s and retaining the original speedo cluster, and who don't want to go through the tedious process of changing the rear axle.
Available here:
https://www.brantz.co.uk/product-page/european-gearbox-sensor-br4
bobxyz
Board Member
- Joined
- Aug 29, 2014
- Location
- Boulder CO
Wow, that's an awesome find!!!
The 4 pulse per rev is the same as I'm running using the cruise control sensor on the back of the speedo - seems to work fine even though it's +-2.5x slower than a real diff sensor.
Please post an update once you try it out. Compared to the alternatives, buying that simple inline adapter and running 3 wires is trivially easy.
The 4 pulse per rev is the same as I'm running using the cruise control sensor on the back of the speedo - seems to work fine even though it's +-2.5x slower than a real diff sensor.
Please post an update once you try it out. Compared to the alternatives, buying that simple inline adapter and running 3 wires is trivially easy.
- Joined
- May 27, 2008
- Location
- Rockland County, NY
I wonder if the adaptor I used to convert from mechanical to electronic speedo would work the same -
then I used a HealTech Speedohealer to condition the signal for the specific speedo I used.
then I used a HealTech Speedohealer to condition the signal for the specific speedo I used.
bgpzfm142
crossmember
- Joined
- Dec 25, 2013
- Location
- Launceston, Tasmana
Will do, although that may take a while - things around here proceed about as quickly as a Prius in the overtaking lane.
Well that, plus iPD tells me the little hat seals I've ordered for the speedo cable won't be in stock for another week, and then they have to be shipped here, so...
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
Has anyone looked at the output for PIN 200 on the back of an LH 2.2 gauge cluster? It's a speed output also, so I'm wondering if anyone has looked to see if THAT would be useful to feed a speed signal to LH 2.4.
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
PIN 171/5 in the 1990 diagram also makes me curious. Details for 171 are not shown in the 1990 greenbook, but it's in the earlier LH 2.2 greenbooks as the Shift Indicator Control Unit. So Volvo kept that output for LH 2.4 clusters and in the 1993 greenbook, 171 is back and shown as the Cruise Control Module.
@Smorgesborg did this iirc
dbarton
Dejected by Volvo Corp.
- Joined
- Nov 17, 2002
- Location
- Prosper, TX
And I found instructions for adding cruise control to an LH 2.2 240 and it uses PIN 200 for the speed signal.
bobxyz
Board Member
- Joined
- Aug 29, 2014
- Location
- Boulder CO
AFAIK the 2 tabs on the back of the LH2.0,2.1,2.2 speedos are the VSS signal for cruise control, which is the same VSS signal used for LH2.4 ECUs. Do you have a reference showing the "Shift Indicator Control Unit"? Maybe that unit uses the VSS and RPM signals.
Pietercc
Well-known member
- Joined
- Apr 5, 2019
- Location
- Stockton,CA
I'm doing a 2.4 swap soon on my GF's 242, and my plan was to use the cruise control VSS. I can report back with a quick article once I confirm it works