OBD 1 Cable Pinout

[CruiseControl]

This project is "how to read the OBD 1 codes of my 1994 Honda Civic DX, using my laptop". While the software is available cheap, finding a serial cable and a pinout of my cables is proving a task. Any information regarding codes and cable pinouts for my Civy would be appreciated. Evidently they are different for every manufacturer. Getting inside my ECM would be nicer than trying to figure out my dashboard lights.
PS. My Check Engine and SRS lights blink when in Self Diagnostic mode. This is not a listed code in the Honda manual...ideas, aside from replacing the ECM?

[SVOboy]

Hmm, quite a predicament, how many times is it flashing on the ecu itself? Lemme look for a code list.

[SVOboy]

<a href=http://honda-tech.com/zerothread?id=1171263 target=_blank>http://honda-tech.com/zerothread?id=1171263</a>
There ya go.

[CruiseControl]

The Check Engine light is NOT blinking, which according to Mitchel's means that the ECU should be replaced, since the code is not listed. The Check engine light is on, and the SRS light(red immediately below) is blinking, at a regular interval. I'm new to this, and figure I'm doing something wrong, however after double checking my plugs etc. everything is correct and the same code, appears :| I'm trying to put together a Code Scanner with my laptop. There is software on eBay for ~ $20, however it uses a Serial Cable http://cgi.ebay.com/ebaymotors/NEW-OBD-I.....QrdZ1 (http://cgi.ebay.com/ebaymotors/NEW-OBD-I-II-1-2-DIAGNOSTIC-SOFTWARE-MILEAGE-CORRECTION_W0QQcmdZViewItemQQcategoryZ43989QQitemZ 4590349204QQrdZ1)

[SVOboy]

How many times is it blinking? That should give you the code that it is giving.

[Matt Timion]

How many times is it blinking? That should give you the code that it is giving.

Honda obd1 and obd0 codes are much different SVOBoy. There isnt' even a window on the obd1 ecu for CEL codes. I'll do some searching on this topic tomorrow.

[DaX]

The Check engine light is on, and the SRS light(red immediately below) is blinking, at a regular interval.

Are you SURE your car isn't OBD-II? My brother's EJ has the CEL and SRS light blink for codes...

[CruiseControl]

I'm not sure of anyting, except that the timing won't advance on my Civic, and I just replaced the Distributor, thinking it was the ICM(ignition control module), and I was in a rush to get to work. The owner's manual doesn't have an entry for OBD or ECM, and Chilton's only mentions "self diagnosis system". There is a three prong connector to the ECM, which I presume is an OBD1 connector. Now all I have to do, is make sure that I don't plug the wrong wires from the Scanner into the ECM and fry it, or my laptop. 3 prongs x 3 wires = 9. 1:9 odds, better read some more.

[CruiseControl]

Here's a thread that says that I have "No Problem", with a check engine light on, although there is no mention of the blinking SRS.
http://honda-tech.com/zerothread?id=1439906
What gets me is that my car has no power until it reaches ~ %50 RPM, and it's very hard to start and sounds weird(missing alot until the foot comes off the gas, and the key returned to neutural). The only thing done, was a swap out of the Distributor :( , which I thought was the problem since it had been so full of water every Fall for so many years. What could possibly not be connected or leaking (vacuum?); new gas filter too. :|

[SVOboy]

Get the right dizzy for it? Could be the problem, I dunno much about them though.

[DaX]

Your blinking SRS light has me the most puzzled - I've never seen that on an OBD-1 vehicle.

Have you checked your timing with a timing light? You should be 16*BTDC with the service terminal jumped. Also check your static mechanical timing...could be off a tooth on the cam sprocket.

I had a problem with my ICM and coil in my turbo LS hatchback...I purchased the bottom of the line MSD unit [the 6A] and built a trigger circuit - now I can run an external MSD coil and no honda ICM [they're troublesome and expensive little bastards]. If I blow a component on my trigger circuit, it will only cost about $6 at most to replace.

[symph0ny]

I'm still trying to figure out how to get diagnostics to work with my ECU... but like DaX I put a MSD (6AL) ignition in my car. I have a 94 civic dx, and when I was reading reviews for the MSD ignition, I read a comment about the instructions for the ICM connection being wrong. Turns out my Hayes manual instructions were wrong too, and I suspect the Honda shop manual gives the wrong wiring description too.

It turns out the ICM ground connecter is not white/blue (that's the tach), the ICM ground connecter is green/yellow.

I'm not sure if you were aware that there are a lot of bad ICM wiring diagrams out there, so you should probably check your wiring.

[CruiseControl]

Checked the Mitchel manual and Chilton's both show EVERY ground wire as either being black or at least having a black component. Glad I have a VOM(volt ohm meter) to check the wires myself. Still not sure why it's wacko, so I brought it to the dealer and am awaiting the verdict. If they want to replace the ECU I'll consider the MSD option. There is a software package named "Uberdata" that seems to be OBD2 compatable and probably OBD1. I'll check soon. Whatever you do DO NOT buy the CD for sale on Ebay that claims to offer OBD1 & OBD2 programs to diagnose virtually every make of car, it's all hacked software, and only for a few European makes, and models. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4592922779&ssPageName=MERC_VIC_ReBay_Pr4_PcY_BID_IT
NEW-OBD.I&II(1&2)DIAGNOSTIC SOFTWARE-MILEAGE CORRECTION
Most of it is actually software from american software makers like AutoTech, that have been wacked with custom packages for mercedes, bmw, etc. I thought Ebay stopped allowing this kind of thing during the 90's its a federal offense to import or export stolen property.

[DaX]

It turns out the ICM ground connecter is not white/blue (that's the tach), the ICM ground connecter is green/yellow.

In my distributor, the tachometer signal is the solid blue wire, but I'm running a 1994 Integra LS distributor [OBD-1].

If anyone is interested in building a trigger circuit for their MSD unit to get rid of the stock coil AND igniter, I can help as I have done it - there's a writeup with pictures on Honda-Tech.

[carsearch95]

The Check Engine light is NOT blinking, which according to Mitchel's means that the ECU should be replaced, since the code is not listed. The Check engine light is on, and the SRS light(red immediately below) is blinking, at a regular interval. I'm new to this, and figure I'm doing something wrong, however after double checking my plugs etc. everything is correct and the same code, appears :| I'm trying to put together a Code Scanner with my laptop. There is software on eBay for ~ $20, however it uses a Serial Cable http://cgi.ebay.com/ebaymotors/NEW-OBD-I.....QrdZ1 (http://cgi.ebay.com/ebaymotors/NEW-OBD-I-II-1-2-DIAGNOSTIC-SOFTWARE-MILEAGE-CORRECTION_W0QQcmdZViewItemQQcategoryZ43989QQitemZ 4590349204QQrdZ1)


WHERE DO YOU GET THE HONDA OBD1 SERIAL CABLE??? I LOOKED ON E-BAY!

[SVOboy]

Where does the obd1 cable hook up to and what does it do?

[Matt Timion]

Try sending Cruisecontrol a PM to find out this stuff. I don't think he's visited this site in a while now.

[DaX]

Where does the obd1 cable hook up to and what does it do?

There is a connection port under the dash on the right side of the car near the door/ecu/glovebox area [this is where it is on my Civic anyhow]. There are two plugs hanging down - one you jump to check your CEL's and the other one is to hook up to the ECU.

[SVOboy]

Interesting. I need to find the not CEL jumper one then.

[DaX]

Interesting. I need to find the not CEL jumper one then.

This is for OBD-1, not OBD-0.

[SVOboy]

Who's obd0 these days anyway? Not me.

[DaX]

Who's obd0 these days anyway? Not me.

I'm OBD-0.

Your car's wiring harness is OBD-0 though [isn't it a CRX?], and you won't have these connectors under your dash.

[SVOboy]

I have the blue jumper connector there in my CRX just like the obd1 cars though, :p