I've done my best to search, but I haven't found the suggestion that installing cruise on a base 07-08 fit (US) should be as easy as wiring the controls to the ECM. All the programming for the cruise should be in the base ECM, just the wires and controls would be deleted.

Has anyone looked into this? I haven't taken delivery of my base fit yet and have not been able to find a wiring diagram. So I'm a little blind (read: ignorant). I would be very happy to find that the cruise is a similar case as the keyless entry in the 09+ (where the receiver is there but the base model just doesn't come with the fobs).

 

Okay, if anyone was curious, you can't just wire in buttons to get the cruise working on a base fit. The wires from the cruise buttons go to the gauge cluster and the gauge cluster apparently does the control of the cruise.

I have gone so far as to wire in the extra wires and see if my base gauge cluster would do the controlling even though it doesn't have the cruise indicator. It does not. Apparently Honda figured out that it was cheaper to make multiple versions of the instrument cluster with and without the cruise components or circuit traces. Luckily though I did not mess anything up.

I am going to research the service manual and see if I can't figure out all the differences with the base and sport gauge cluster. I may end up buying a sport gauge cluster and selling my base speedo.

Does anyone know if the sport and base clusters are interchangable? Has anyone tried this before? Has anyone replaced their stock cluster with a salvage yard cluster?

I don't mind losing a little money on buying and selling. I just don't want to spend $350 on a aftermarket cruise box. Yes, I am that cheap and I have it stuck in my head that I should be able to do this myself. Plus, I would like to figure it out to help everyone else. Honda should not have skimped on cruise. They should know that hyunda is stealing their market...

 

That's interesting that the cluster controlled the cruise control. Does it have some kind of memory or control chip on it? Seems strange to me that there would be a cost savings to make two types of control panels. I used to work for Ford as an engineer and it would seem a strange thing to do, as volume discounts usually beat multiple configurations.

 

I would think the same thing. My best guess is that they have the same board in them, but they just omit the extra component or two. I would have guessed that the extra warehousing and logistics cost would have outweighed the components, but I guess you can't have the base model dashes showing up with a "cruise" light. So, if you are going to stock different gauge inserts, you might as well save a few pennies by omitting the components.

The more I think about it, the more I think this may be hopeless. The ECU has a different model number between the sport and base model. Even if I replace the base instrument cluster with the sport, the instrument cluster would likely just pass the set/resume/cancel commands on the ECU where they would be ignored.

Any ideas? The trans and motors are the same between the base and sport models, aren't they? (I can't find different model numbers.) Or what's the justification for two different ECUs? Still curious if anyone has put a sport cluster in a base?

 

I am trying the same thing on my 2008 Fit Base. (I bought the remote lock honda kit for about $150 and now have remote door locks). For the cruise control, I have bought a 2008 Sport steering wheel with paddle shifters and the cruise buttons (hasn't got here yet). I am not sure if the cruise and paddle shifters have wiper connectors on the back of the wheel or not. I suspect I may need a sport steering column. Anyone know? I have spotted the drive by wire throttle control unit at a salvage. But it might be without required wiring. Does it take more wiring to put it on the ecu (right kick panel)?

Also, what does it take to make the paddle shifters work on the base?

 

Yeah, you need the cable reel out of the sport, too. It may be cheaper to buy that from majestic.

The cruise switches wire to the gauge cluster. You need the sport gauge cluster.

The paddle shifters wire to the pcm. I know from my own testing that the base ecm ignores the shift input. You need the sport pcm.

If you already have the wheel, you can buy the cluster on ebay, the pcm from a yard, and the cable reel from majestic. Then all you need would be to run your own wires and convince a dealer to try and re program your keys to to the new pcm and the mileage to the cluster.

If you just want a track car and you live somewhere where vin tampering isn't illegal, you could pull the pcm, keys, and cluster from a sport and only reprogram the throttle body.

I may be wrong, but I think that covers all the functional differences. And before anyone starts yelling, the shifer and tranny are the functionally the same. You are just locked out of the last two positions on the sport model.

 

I know it may be different, but I tried wiring switches to the gauge cluster on my 2010 without success. The "cruise main" light comes on but it doesn't engage. The hardware (pin,lights) seems to be there, but the software or pcm itself may be different. That ends my quest for cruise control unless I can find a '11 base cluster. Or get an aftermarket kit and use OEM controls and the light on the gauges as an indicator only. Good luck! I sure hope It's a different story for the GD.

 

That further confirms what I've found. The sifters input to the pcm and the pins at the base pcm are high just as they would be on the sport pcm. When you pull the pin low like the sport, nothing happens. The part numbers are different and the programing is too. Since the cruise is done by the pcm, the signal just gets ignored.

I still don't know why honda would bother with different parts. But I've got new ideas for getting the cruise to work.

 

Hi FitnaGo,

I also have a base AT 2007 Fit, and about a year ago I did the same research project that you are doing with the Honda manuals. I came to about the same conclusion that it would not work due to differences in the gauge control module. I thought about doing the same test that you did by connecting switches to the gauge control module. However, there is one thing that I found that has not been mentioned in this thread, which is that there is an additional brake pedal position switch that is present in the sport that is related to cruse. This switch is normally closed and is connected to the ECU (connection D8) to indicate that the brake pedal is not pressed. Did you add this switch or simulate it in your test? I would guess that without it, the cruse would not engage.

Also, what makes you sure that there are differences in the ECUs between the base and sport that are related to cruse? I can see that paddle shifters would require some major code changes in many parts of the car that could account for there being different models of the ECU, but couldn't the cruse differences be isolated in the gauge control module? In any case, this is all pure speculation without testing and, at the time, I decided that it was not likely enough to work to justify the complexity of doing the test.

Another interesting fact is that the Canadian LX model started-out without cruse which was later added to that model. Unfortunately, I have not found a parts catalog that showed the Canadian models to see if there were part number differences for the gauge control module between the LX and sport models.

My tentative parts list was:
36770-SLN-A01 - Cruise Switches
77901-SLN-A00 - Steering Wheel Harness (x2)
77900-SLN-A11 - Cable Reel
36750-SMA-003 - Brake Switch

With new Honda OEM parts this would have set me back about $240. The reason for 2 of the steering wheel harnesses was to cannibalize one to get the connector for the back of the cable reel which is different between the base and sport (the connector on the steering wheel side is the same as the one on the steering column side). There is also a lot of wiring that would need to be added between the cable reel and the gauge control module as well as the previously mentioned brake switch wiring over to the ECU. None of this wiring is present in the base wiring harness. This whole approach would have assumed that the base gauge control module and ECU would be able to process cruse commands.

Also as a side note, the gauge control module does have a CPU (according to the manuals) and presumably firmware as well, so it is capable of doing many things.

I don't know if any of this is useful, but this is where I ended-up with my research. I am curious about your new ideas for getting this to work.

 

Huh. I might look into that brake switch and try again. thanks!!

 

I admire you guys for trying so hard to put the cruise in. While I would love to have cruise in my Base I knew going in that the job might be more trouble. I worked with this type of stuff for years in my job as a technical trainer. (Toyota, GM, and even a couple of years with Chrysler). As you have seen there is much more to this stuff than connecting a few switches. The PCM programing is different as it has to factor in the inputs. Then you have the cluster that folks have found. Its a link in the network and it has to be correct. Also, in most vehicle these parts all have to hand shake. Sometimes they have to be programed to work together, something only a dealer has to tools to do.

I decided that it was not worth the trouble to go to these lengths. Next time just buy a Sport with the cruise. I am not due for a new Fit replacement until the next generation, rumored for 2014. I just picked up a 2012 CR-V EX-L and it comes with a cruise...problem solved.

 

@hans471:

I understand what you are saying. I personally would not go as far as swapping either the gauge control module, the ECU, or both. There would be many unintended consequences of this. Also, at that point, it would be easier and probably cheaper to install a 3rd party cruse!

However, having said that, it doesn't seem that anyone has conclusively proved that adding the missing cruse wiring to the base gauge control module and ECU will not work. Unless FitnaGo added the brake pedal position switch for cruse and didn't note that in this thread...

@blackprlfit:

I think you are closer to getting this to work than us GD owners. At least you are getting lights! The only caution I would add is that you should check any of my statements against the GE manual since all of my research is based on the GD.

 

I do admire the people who will try this stuff. There was a time when I enjoyed the challenge. But, after years of doing technical work eight, ten, or more hours a day...when it came time to come home the last thing I wanted to do was beat my head against the wall on things like this.

On domestic vehicles where electronic throttles are used the PCM has to be programed to make the cruise switches work. The problem here was that the PCM was programed by VIN and the VIN had to call for that system to be in the car or it was a "no-go". So, you would have to have a PCM AND a proper VIN code to go with it to "fool" the system. There are layers of security built into the programing and its hard, if not impossible, to fool.

But, perhaps our Asian cousins are not this tight on how they do things. However, on the Honda Owners Group I can plug in my VIN and it will give me the call-out on every option on the vehicle. So, good luck with this. Easiest fix might be find a wrecked Sport and pull all the parts out. Oh, is that "easy" just to get a cruise?

 

I have the GE manual. I'll take a last look when it gets warmer outside.

 

Jbox, I wish you would have told me about the brake while I had my car all tore apart...

I was just about to tap the wires that went to the throttle and sniff out the voltages using a microcontroller. I was hoping to see if there were any self checks. From the Honda diagnostics tool I can see that the two sensors run between 0-5 volts and the second accelerator position sensor is always half the voltage of the first. So, it's really 0-2.5 volts.

I just can't figure out if there are self checks to make sure an idiot like me doesn't just hook up a potentimenter in place of the accelerator pedal. If there aren't, it will be super easy for me to make my custom cruise. If there are checks, I'll have to be smarter than Honda.

I have no idea I why I put soo much time into this. I just like the challenge. Plus, I graduated recently. I'm still in the cheap college mindset.

 

And I don't think it's a matter of security and vin checking. I just think that they deleted the wires and they found that it would be safer to have the inputs inactive rather than letting the code sit on the PCM waiting for the inputs to float high or low and have a runaway throttle event... Congrats to Honda for having such an efficient inventory system that they can have multiple versions of the same part that vary in functionality by so little. Shame on them for going through so much trouble to prevent the consumer from having such a basic feature.

Sorry I've been away. I finally got my old car sold and the fit is now my primary transportation. That means more incentive to get this done.

 

Sorry about that. I don't always check these forums regularly.

 

It was a pretty day today. I tore the cluster apart to confirm that the signals from the cruise buttons will not communicate to the pcm/ecm/ecu. The inputs at the gauge cluster are just pins that lead to nothing. I connected the HDS and can see from the computer that no input will trigger any of the controls. I did not check the break, but given the the computer will not register the shifters and the gauge cluster will not register the cruise signals, there is no reason to check the break.

Yes, I know that the cruise will not activate without the break signal, but the HDS readout tells you all the signals the gauge cluster is getting regardless. That includes the door lock when you try to lock the door while it is open.

(HDS is the Honda Diagnostic System. I would recommend anyone who has to troubleshoot newer honda vehicles get one.)

 

I agree with your assessment of the situation given the troubleshooting instructions for cruse in the service manual. I don't have an HDS but was thinking that this would be a good way to go for checking the functionality of the cruse. No point in trying it while driving at that point. Too bad they didn't make this easy to add.

 

IT WORKS! IT WORKS!

I have cruise control on my 07 base fit! I did it all myself and it didn't cost more than 40 bucks!

I had to program a microcontroller and create a few circuits, but it all works like a champ. It took me forever, but if I had to do it again, I could do it in a day or less. All you do is read in the accelerator pedal position sensors and output a pulse width modulation signal out and into a second order low pass filter. I tuned to filter to about 15 hz to get my APP sensor A. The output from that can go through a voltage divider to get your second APP sensor.

If you understand what I just said, PM me and I'll see if I can help fill in the holes. If you don't understand the jargon, you should probably buy a kit. I dont mean to be rude. I just don't want someone to have a run away car because of something I helped them get into over their heads.

Anyway, I'm really tired. It's after 1 AM here. I finally had to give up on fine tuning the PID controller. I just had to gloat.