Civic HX Lean Burn "Econo" Light - Fuel Economy, Hypermiling, EcoModding News and Forum

cbaber · 07-31-2013, 03:13 PM

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:

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.

cbaber · 07-31-2013, 03:19 PM

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.

02ws6 · 08-01-2013, 02:31 AM

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..

tony_2018 · 08-03-2013, 12:49 AM

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.

Jakins · 01-13-2014, 11:58 AM

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.

Xist · 01-13-2014, 05:44 PM

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

tony_2018 · 01-13-2014, 08:56 PM

Quote:

Originally Posted by Jakins

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.

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.

firehawk618 · 03-10-2015, 10:58 PM

Quote:

Originally Posted by Jakins

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.

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.

Jakins · 03-10-2015, 11:14 PM

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.

firehawk618 · 03-10-2015, 11:22 PM

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!