I recently bought my son a 1993 civic dx (1.5 16 valve) as his first car. When I bought it I didn't notice that the check engine light did not turn on when I started the car. The car starts and runs fine but I can't get it smogged because the cel does not turn on when the key is turned. I checked the wiring from the ecu and the bulb itself and their fine. I noticed some spliced wires near the ecu but can't figure out what the problem is. Any ideas? Thanks in advance !

 

Could be the cluster can you go to a junk yard(pick n pull) and grab one and try pic of spliced wires tho ??

 

Checked a different cluster already with same results. Ill try to get a pic of the harness tomorrow. Thanks!

 

What wires did you check? How did you check them?

 

Did you just do a visual check of the bulb, or did you resistance test and/or replace it with a known working bulb?

 

Replaced the bulb with a working one. I checked the wiring by grounding out the cel wire from the ecu and it came on...if that makes sense.

 

Makes sense...sounds like the ECU is bad.

 

So you think it's the ecu even if the car runs fine? Any idea which model ecu I need?

 

Post clear pictures of the spliced wires near the ECU.

I think you need a P06 ECU. Verify by checking the label on your ECU behind the passenger kick panel. Also make sure to match the ECU to the transmission - auto versus manual.

 

Thanks for the flow chart! Right now it has a p05 ecu in it. I believe it's supposed to have a p06. Ill chexk everything out via flow chart later...thanks again!

 

What engine do you have?

 

We have the 1.5 liter 16 valve motor in it.

 

D15B7 or D15B8?

https://honda-tech.com/forums/showpo...5&postcount=12

 

The block is marked D15B7.
The reverse lights work but the oil pressure light does not. I also noticed that a wire is cut just above the oil filter.....oil pressure sender maybe.

I would post photos but I can't seem to figure out how.....maybe because I'm still a trial member for a few more days.

 

D15B7 = P06 ECU

You definitely want the oil pressure light working, so repair the sender unit wire. However, that's not causing the CEL problem. Based on your collective information, the ECU is almost certainly bad and doing all the tests in the diagram is worthwhile and should confirm this diagnosis.

Upload your pictures to PhotoBucket and then paste the IMG code for each picture into your post.

 

Ill run the test tomorrow but it looks like its time to look for a new ecu.

 

Yep. Shop around for good prices from reputable sources.

 

Any recommendations?

 

Check the FS/WTB sticky at the top, and the Marketplace when you get past Trial User status.

Other Honda/Civic forums and eBay are other possible sources.

Caveat emptor.

 

Picked one up from ebay. Hooked it up and guess what.......cel worked as it was supposed to! Thank you everyone for the help! Now on to the next problems lol