From the "Here he goes again..." dept.:
OEM JDM 5G 1992-95 Honda Civic Traction Control System (TCS) Theoretical Retrofit DIY
I havenít performed this retrofit, nor do I intend to because I donít plan to own a B16-series motor. However, Iíve done some research on whatís involved and thought there might be interest in a DIY for how to go about it theoretically, if someone was interested in assembling the correct parts to attempt it.
We all know that the Japanese Market got some great equipment on these Civics. Some of you might even know that a Traction Control System (TCS) was available on the JDM EG6 and EG9 Civics. See an example of the TCS switch in Figure 1. Well, thereís a lot of mods, swaps, and retrofits Iíve seen done to these 90s Civics, and thereís barely a single question that hasnít been asked and answered on the forums to date. K-swaps, J-swaps, XYZ-swaps? Check. Comfy CL seats? Check. AWD retrofit? Check. The list goes on. However, one retrofit that I have never seen attempted is that of the OEM JDM TCS feature on an LHD 5G Civic.
Figure 1. TCS switch.
Iím going to set about helping to change this. Even though I donít plan on doing this mod personally, I think it would be cool to see someone else attempt it. I can think of a dozen reasons why it hasnít been done yet, though: Availability of parts mainly comes to mind, and a lack of interest perhaps, but also a lack of documentation. I canít do much about the former two, but the latter I can do my best to address. There was a time when I thought this retrofit wasnít possible, but with more research I have now changed my mind. For some reason I thought it required more hardware than it did, but really itís all electrically and computer-driven.
Herein, Iíll provide a list of required parts, and some resources to consult. Unfortunately, this install is not for your typical broke-*** Civic owner. Sorry. Actually, if you just want TCS functionality without all the attendant OEM fanciness, it will probably be cheapest to install a Hondata Traction Control. But, this write-up is for someone who wants to use all the OEM technology and features of the original unit, including using the original gauge cluster. Thatís not to say you couldnít hybridize the two systems, maybe, if you were so inclined - especially if you want to use a different motor.
TCS basically works by piggybacking on to the ABS system. The TCS brain monitors differences in wheel speed and applies the brake to reduce torque/wheel speed. This can be a front wheels vs. rear wheels problem, or a left vs. right front wheel problem where the application of the brake to one wheel mimics the function of an LSD and shift traction to the wheel with grip. I wonít claim to be an expert on the topic. Here is a little video
of the basics of operation.
Or, "Don't point fingers, you only have yourself to blame"
Every effort has been made to make these instructions as complete and accurate as possible with the information I have available, but no warranty or fitness is implied. The information is provided on an ďas isĒ basis. The author(s) and the website/publisher(s) shall have neither liability nor responsibility to any person or entity with respect to any loss or damages or inconvenience arising from the information contained herein, nor due to any omissions. Read: Don't muck up your vehicle and try to blame me or anyone else. You are responsible for your own due diligence and research.
Like I stated, not for the faint of heart:
- 5G Civic with functioning ABS (or an ABS retrofit - yikes)
- ODB1 B16 Motor
- JDM TCS-enabled P30 ECU - p/n 37820-P30-930 or 37820-P30-N21
- TCS Switch (Figure 1)
- Gauge cluster with TCS symbols (Figure 2)
- TCS Brain - p/n 39900-SR3-003
- JDM TCS-enabled ABS Brain - p/n 39790-SR3-981
- Steering column sensor - p/n 53390-SR3-N52
- Wiring between all this stuff
The TCS Brain talks to the ABS brain as well as the ECU. Both of these parts are different on a JDM EG6/9 with TCS vs. a non-TCS JDM EG6/9, so you need all this stuff. Since TCS only came on the EG6/9, and TCS talks to the ECU, it follows that this retrofit is only possible if you also have a B16 motor installed that requires the P30 ECU. Iím not sure it matters if itís a JDM or CDM/USDM version of the motor, but if you have emissions requirements that you canít pass with a JDM ECU or motor in your jurisdiction, youíre going to have to consider carefully how you plan to do this swap. To get really fancy you may consider piggybacking both ECUs together somehow, or seeing if the TCS functionality of the JDM one can be transferred into the CDM/USDM one.
Figure 2. EG6 cluster with TCS symbols. (Courtesy BlueIntegraBoy).
Try to get a cluster that includes pigtails for the breakout box mounted on the back (Figure 2a) because these size connectors are actually uncommon due to the number of pins on them.
Figure 2a. Pigtails required on back side of TCS cluster. (Courtesy BlueIntegraBoy)
The steering sensor is a bit of an unknown currently to me as to how it works and exactly what it does (Figure 3, 3a & 3b). But, it appears to slip over the steering column under the steering wheel. However, know that other Honda vehicles from this era also had a similar sensor, such as the NSX and the 94-95 Acura Legend.
Figure 3. EG Steering column sensor (Part # 14).
Figure 3a. EG Steering column sensor, when mounted (Courtesy: derek_k)
Figure 3b. EG Steering column sensor, when mounted, showing connector (Courtesy: derek_k)
Well, youíre really in uncharted waters here. However, once you have the above parts, itís a matter of connecting all the wiring between them.
Here are some wiring diagrams which will make your life easier. JDM TCS, ABS, and DOHC VTEC ECU (Figures 4, 5 and 6, respectively - click link above each to view larger size):
FIGURE 4 LINK TO LARGER VIEW
Figure 4. JDM TCS Wiring Diagram
FIGURE 5 LINK TO LARGER VIEW
Figure 5. JDM ABS Wiring Diagram
FIGURE 6 LINK TO LARGER VIEW
Figure 6. JDM DOHC VTEC ECU Wiring Diagram
Finally, if you need to consult the service manual for TCS to diagnose a problem, and you happen to also read Japanese, well, youíre in luck there too
And thatís all I have for you right now.
Good luck, and hopefully this idea can gain some traction.