Hi,
I have a '94 Accord Wagon LX with about 160k miles on it. It runs pretty decently most of the time.

But a couple weeks ago I was at a stop-light when I seemed to hear/feel a 'click' from behind the dash and the Check Engine Light came on. The car immediately started running poorly (idle lower, sputtering a bit). Later that day when I went to start it, it ran fine for a few minutes, then the same thing happened and I 'limped' home.

The next day the CEL came on immediately upon starting, and it ran very poorly over to my mechanic. When he tested it, though (shorting the connector), the CEL just stayed lit continuously. So he said there was no code for him to diagnose and that my computer might be bad.

Since then, it has randomly gone from running fine with no CEL; not starting at all with CEL; not starting with CEL a few times, then running fine. Today, after a couple weeks away, it started and ran fine, but dropped RPMs temporarily or stalled a couple times, but with no CEL.

SOME NOTES:
- I have a bad oil leak. I have found a couple times that if the car is really low on oil, it won't start (turns over but then immediately dies). When I put oil in, it starts and runs fine. Thought it was 'a protection feature'.

- When diagnosing, only the D4 light blinked continuously. Mechanic thought it was my speedo problems (speedometer only works about 10% of time over last year or two).

- Mechanic said at least one of my spark plug wires is in need of replacing.

QUESTIONS:
- So is there any definitive way to check if the ECU is bad apart from replacing it? It seems like this might be it, but I've heard they almost never go bad. I would get one from a junkyard.

- Any other things that could be tested? I don't know where to start.

- Any ideas on the low-oil issue (not starting)? The Honda service manager looked at me like I was crazy when I asked about this 'feature'.

THANKS A LOT! My mechanic doesn't know where to start.

 

There's no measurement of oil inventory, so that can't be a "feature". If your oil was so very low that the engine begins to seize, then it shouldn't suddenly be OK when you add oil. So ????

If oil is leaking into the sparkplug tubes, that might explain misfiring & stalling, but again it wouldn't suddenly get better when you filled the oil. It might get better when you wiped out the sparkplug hole...

When he shorted the connector, did the D4 lamp blink? Tell us THAT error code.

 

OK, my car had been running pretty decently this week since I got back from vacation. Not CEL or poor running.

But today, out of nowhere, the CEL came on steady and it immediately started running poorly (low power, lower idle - no stuttering or missing, though). I also noticed that the D4 light blinks continuously, but I think that may have to do with my speedometer not working.

The car kept running this way until I turned it off for lunch. Then, after a few seconds being started it happened again. So it has stayed pretty steady since it started happening today.

So I shorted the plug to check the error codes. This is what I get:

CEL: solid lit. Absolutely no blinking at all.
D4: blinks code 14.

I then pulled the fuse to reset the computer, and the same behavior started as well as the same codes (or lack thereof) produced.

- So does this point to a bad computer??

If I don't have a code, I have no way to 'fix' a problem. The car shifts fine, no probs with the tranny (just the speedo not working).

- Can the computer actually be tested? Or do I just have to buy a new one and see if that fixes the issue?

Thanks again!

 

When the speedometer is not working, is it stuck at ~19mph? Does the cruise control work when the speedometer is not working?

A bad ECU is listed as one of the causes of a D4 code 14. I would suspect a bad ECU from the CEL not putting out a code.

I would check out car-part.com to find engine computers from local junkyards at reasonable prices. See if you can return the part if it doesn't fix your problem.

 

Well, the speedometer only works about 10% of the time over the last couple years. I'm pretty sure the cruise control works OK, though.

So I suppose at this point I'll try to find a used ECU and swap it out. I think the intermittent issues would be hard to diagnose. If this doesn't do it, it might be a short somewhere which I imagine would be a nightmare to track down.

So is the ECU very difficult to swap out? I've pulled back the carpet to see it, but does it need special tools or anything to keep all the wires connected properly?

And does a swapped out ECU need to be programmed on my '94? The dealer told me it might, but I've also heard that's only on the newer cars ('96 & up). I have the exact part number for my ECU.

And thanks for the tip on car-part.com. That could be very helpful.

 

If the cruise control works when the speedometer does not, then your speedometer is the problem. If you know how to solder, you can try to remelt some of the joints on the speedometer board. Do a search for solder and speedometer to find a long thread about that.

As for the ECU, you just have to pull back the carpet, unbolt the plate, unplug the ECU and TCU, then unbolt the ECU. Installation is reverse. No programming is necessary on your car. Download a 94 accord shop manual from the spooner link in the online manuals thread in the DIY section.

What is important for the ECU is that it is from a 94 or 95 LX wagon that is an automatic transmission (if your accord is automatic). The part number is 37820-P0J-A60

 

Great thanks! I found a used ECU close by for $110 delivered. Should get it on Wednesday. I had the part number as well, so I made sure it was correct.

I hope this does the trick. I'll let you know...

 

Well, the computer went in easier than I thought it would (pulling the carpet back enough was the trickiest part). And for the last couple days, it's been running really well.

Thanks for the advice and help here!!! So glad this appears to be only a $100 issue.

In case anyone else has similar issues and a new ECU does NOT fix the problem, I also found this thread that might be helpful: http://answers.yahoo.com/question/in...4144045AAqJkck

 

So i kind of have the same problems. used to have the Tranny give me code 14, i replaced the fuse, because it seemed to be broken, my car works fine however when i check the CEL code it gives me the CEL stays on, so im thinking its a bad ECU?

 

"Kind of" the same problem?

Does the CEL light up when you're NOT jumpering the SCS connector (when you're driving)?

If there are no stored error codes, and the CEL is not coming on, then the normal proper behavior is that the CEL stays on solid when you jumper the SCS connector.