just went to get car inspected. everything else passed as far as emissions but it failed the bulb check so automatic fail. $50 for this crap. Im not throwing any codes, cel light does not come on when you start the car as it should. im thinking its either the bulb,fuse or worse some electrical problem I would have no idea how to trouble shoot. can someone confirm what fuses I should check to see if thats the issue? Im going to try switching out a bulb now.

 

Any luck with the bulb?

What car are you driving?

Read through this, it may or may not help you with the problem, but nonetheless its good information to know

http://techauto.awardspace.com/ecu.html

 

I can confirm its not the bulb. I had 3 spare bulbs. tried swapping in each; nothing. then tried using a bulb I knew worked fro the turn signal. still nothing. 98 dx hatch

 

Dig up a wiring diagram from your battery, fuses ecu and cluster.. I believe the wire going to your cluster for the CEL is green/orange

 

ok will do. also thank for that site you provided. are there 2 ground locations on the thermostat housing? i checked that ground and it looked ok. tried unscrewing and cleaning it a bit but i guess thatd be too easy

 

Is the socket getting power at all?

 

I dont follow? are you referring to the ground or fuse box under hood? btw Ive checked the backup 7.5 fuse. thats not it.

 

or did you mean the ecu itself?

 

No the bulb socket

 

just tried a totally new cluster which im sure works. leads me to believe its possibly the socket pin on the connector itself it was mentioned it was green/orange. whats the tool called that I would need to test if its getting power? a multimeter of some sort?

 

and is this it?

 

When you turn the key from off to ON(II) [engine off], does the oil pressure warning light turn on and stay on?

What car?

 

yes it does. 98 dx hatch with a d16y8 eng/tranny P2E ecu. I bought the car like this. Im fairly certain its using an ex wire harness as well

 

In your picture, the Yel wire (next to the Grn/Orn wire) should have battery voltage to body ground with the key in ON(II). You can use a multimeter or test light to do the test. If the Yel wire has voltage, reinstall the CEL bulb and cluster and then move to the next test.


Unplug ECU connector A. Turn key to ON(II). Ground pin A18 (Grn/Orn wire) in the connector to the metal frame under the dash. Does the CEL turn on? If not, check whether the Grn/Orn wire is cut near the ECU connector.

 

Ok so I got my hands on a test light. I can confirm the yellow wire does have voltage when key is in ON(II). I will confirm the next test. Before I picked up a test light I did take out the ecu and take a look at it. I didn't see any obvious cuts but I will look a little deeper and confirm. I will report back . Thank you all thus far.

 

so just got done back pinning A18 with key in ON(II). the CEL light DOES come on! So correct me if im wrong, if something was cut somewhere along the way it would be impossible for the CEL light to come on even with pinning A18 right? could this mean its a fuse this whole time? I just visually checked the fuses before I got my test light. which ones should I recheck to confirm they are working correctly? Thanks in advance

 

bump