Civic HX Lean Burn "Econo" Light
 

Ok guys I have seen threads in the past exploring the possibility of having an indicator on the dash for when lean burn is on. The European Civics with the D15B 3-Stage Vtec-e motors had a dash light marked "Econo" in the place where the US civics have the cruise control light. This light is on when lean burn activates.

Here are resources covering the D15B:

D15B 1.5l SOHC VTEC
EK3 Civic Vi Multimatic

Now that I know that Honda created the ability to monitor lean burn, I am curious if I can adapt it to my US model d15y5 lean burn motor.

Plenty of people have swapped in the d15b 3 stage vtec motor into US cars with the correct ECU (P2J-003) and had the Econo light working. I also found out the Econo dash light is controlled by pin A30 on the P2J ecu. Here is a diagram:

http://imageshack.us/a/img51/782/english2.png

Here is a thread that describes how to swap in a d15b to our US civics, and it also explains how to wire up the Econo light to work with this swap:

JDM D15B 3-stage, P2J ECU, EGR, O2 Sensor, Wiring Checklist, PICS! - Honda-Tech

My question is if I can buy a P2J ecu and adapt it to work with my d16y5 so that I have the ability to add the Econo light. I am also researching if the d16Y5 ECU has the same A30 pin that controls the econo light, and maybe the function is there but not used on US model HX's.

I'll continue to update this thread as I learn more. Feel free to chime in with anything that could help out.

It appears A30 on US D16Y5 ecu's is for the "shift up light".

Can anyone with a 96-98 Civic HX confirm the existence of a shift indicator light? On my cluster, the spot where it is suppose to be has a blank plastic piece. However, on other forums many with Civic HX's report having the functioning light.

Update: According to Majestic Honda (honda parts supplier) the 1997 M/T Civic HX's were the only ones to come with the shift indicator light. For some reason it was not available in any other year. Or at least according to the parts diagram you cannot buy it for any year but 1997.

May no longer be available for any other year. There is alot of parts Ive ordered for my CRX from there and many I searched for just werent offered due to availability.

That 3stage ECU will not be easy to acquire. But due to honda's vast interchangability and the support recieved from the aftermarket side of the world you can use a "chipped" vtec ECU. This will require some modifying to make work but has been done and not to mention the "custom" tunes that tuners can give these cars are second to none.

I believe there is a few guys on here running custom tuned ecu's for gas mileage and maybe even performance. That 3 stage would def be the best for both worlds..

Using the 3 stage vtec ecu on d16y5 is actually interesting.

edit: But you will need to repin the original vtec to the second vtec.

Yo I had an idea the other day. I'm going to test it out. The shift light comes on t
when you have really low load in every gear but 5th. Sooo all you gotta do is find out what wire tells the ecu that the car is in 5th, disable it and bam, you got an economy light. It would be perfect for anyone without an mpg gauge. Im going to try and figure it out and report back.

I often get an "SES" light. Is that telling me to shift? :)

The ecu doens't gauge what gear you're in. It gauges MAP, TPS and VSS. The 3 stage vtec ecu gauges those and then decides to let you into lean burn mode.

Resurrecting an old thread because I am going to be swapping D16Y5 in place of my D16Y7 in the next 2 weeks.

There is no 5th gear sensor. I'm betting money that if the shift up light doesn't come on in 5th it's because the ECU sees the RPM + vehicle speed and knows it's in 5th gear.

I bet you are right. well ever since I swapped my y5 into a 4door dx I havnt had a shift light. because the dash harness is different and I dont know what the 4 wires to light go to.

I am also swapping into an LX.

I am going to re-purpose my cruise control light into a shift up light.

I will let you know how I did it when I am done.

Also, I bet you the reason that HX's never got cruise control.......is because of that light on the cluster!

BTW I see you're getting 54 mpg, are you really hyper mileing or are you just getting that driving it easy?

I'd love to hit 50.

I have had 50 MPG tanks--twice.

Is this just driving normal, not doing super mileage stuff?

i got 58 mpg tanks 2 times in a row wuth my old hx chassis. I can get 47-50 mpg really easilly with no aero mods. when I do all my aero mod stuff ill be getting 55-60 again. yah I looked at the wire diagram and it apears to go through the cruise control but my dx chassis doesnt have that. if you have any swap questions or manual to auto questions lmk. I know alot more then id care to admit about these things lol

My best tank in my hx was 51 mpg all highway with no aero mods

I'm uploading pictures of the shift light mechanism and the plug, I put led lights in my srs and shift light and the modules were identical. So if you have the white plug that looks like the srs plug you should be able to plug it in and have a shift light

Please click thanks next to my post lol
http://i758.photobucket.com/albums/x...pslqsjpz35.jpg
http://i758.photobucket.com/albums/x...psjmdgmxn4.jpg
http://i758.photobucket.com/albums/x...psohztlceg.jpg
http://i758.photobucket.com/albums/x...psr60ewxxl.jpg

Thanks for sharing the info's!

I have a CRV cluster in my car now so I have a vacant ABS light I can use instead of my cruise light since it does function.

I time the lights the absolute best that I can. If I am half a mile from a light and I do not think I will make it, I EoC. I removed my power steering and have a grill block and air dam. My tires are at 42 PSI. I drive 55 MPH on the freeway.

The hx has neither abs or cruise so I can't comment on those functions. For all I know the shift light could simply be the rpm at which an ex model is able to engage or go into cruise control

http://i758.photobucket.com/albums/x...psycp2gfog.jpg

I have searched and searched and am probably missing it.

Can someone explain or post a link to installing a "lean burn" indicator?

Thanks!

I am confused by this statement.

Can you clarify for me?

Thanks!

You can not simply install one, you would need a jdm 3 stage vtec d15b and wiring and follow the instructions written by a member who has a 4 door green lx.

The best way to see if you are in lean burn is by monitoring the secondary 02 sensor to see when voltage reads 0. You can use a scan gauge or mpguino but it's also easy to tell with a vacuum gauge

I wasn't sure what you meant with a CRV with abs and cruise control

I checked out the SRS and ABS modules. Unfortunately the ECU sends a ground to the bulb to illuminate it.

Those modules take a positive reference to turn them on.

I decided to keep my Cruise control light in tact. I'm certain that one would have worked fine as you indicated.


I ended up using my seatbelt light as the up shift light.

Works fine.

If it takes a ground to light up would the power readings from the secondary 02 sensor at 0 volts illuminate the srs light for a true lean burn indicator

No that works off millivolts and tapping anything into it will skew the readings.




Hmmm, since my wide band has an output I won't be using then what you say would be possible but not connected directly to a light. Simply too much current draw.

yo. so I have my plug and my hx cluster from my old hx. but I dont know what to wire my 4 wires too. have we figured that out?

When I get home I can pull up a schematic.

The picture of the back of my shift light makes me curious.

H/f white referring to the plug I'm assuming
eco green.

Can you post the y5 ecu schematics if you have them see if there was a pinout for the green plug

I think what the printed circuit is saying the shift light connector would be white.

Cruise control OR the eco light connector would be green.

Schematics to come.


EDIT: I cannot attach them they are too large.

PM me your email addresses and I will send them to you.

IF using the CC / Upshift lamp board there's really only 3 wires you need to worry about.

1. Power "should be yellow" and can be found by tapping into your SRS or ABS light connector. The wire should be the same color.

2. Ground "should be black" and can be found by tapping into your SRS or ABS light connector. The wire should be the same color.

3. The third wire is what triggers the light to come on. That one goes to pin A30 on the HX ecu *wht/red*. That wire from A30 also goes to the green plug just outside the ECU. IIRC that one is pin 5. The color will be the same *wht/red*


What I did on my car since I wanted to keep the CC light in tact and the SRS / ABS lights use a POSITIVE trigger vs NEGATIVE trigger is to just use my seatbelt light.

That light is always hot on one side and takes ground to trigger it.

Should the upshift light go through a ramp up module to keep the load off the ECU? I do not know. So far mine's been working fine.

I speculate the CC / Upshift / Eco light has a circuit board so it can dim with your factory dimmer. Do not hold me to that though.

If load on the ECU is a concern I would suggest using a LED in place of the bulb in the seatbelt indicator and a diode if necessary.

Does your eco light come on in 5th gear or is it just our dummy up shift light.

Reading up on the d15b ecu makes me want to see if I could plug and play one into the hx to control y5 lean burn

It's just a stupid upshift light, sorry if I wasn't clear on that.....

There's no eco light capabilities in our HX ecu's in North america unfortunately.

The pin that would light up the eco light instead is programmed as a shift up light.

And I bet you are correct on your white plug / up shift light theory.

My LX did not have a white plug back there at all. It had a green one instead.

cool man. thanks. just curious though. what is the 4th wire? it will work without it?

I'm fairly certain that 4th wire is to dim the light at night when you have your headlights on.

For your upshift light I am showing the following:

Pin 1 = Red wire > dash lights
Pin 2 = Red / Blue or Red / Green > ECU upshift pin
Pin 3 = Black > ground
Pin 4 = Red / Black > dash lights
Pin 5 = Yellow > power

you rule man. been trying to figure this **** out for a year

Any ? just let me know, I have all the schematics and had to do basically what you're doing for that light.

It's not for dimming as it is a constant color.

I Was googling trying to find a low voltage sensor, basically something with an independent power source to illuminate at a programmed low voltage. Anyways ended up buying a cheap $7 tiny volt meter with an independent power source to wire to my secondary o2 sensor readings. It's small enough to hide in plain sight.

I lack the engineering skills to create a sensor to illuminate at less than .9 volts

http://www.amazon.com/dp/B00C58JGE6/...Mini+voltmeter

I assume you don't have an ultra gauge?

Nope, keeping it simple and cheap