CEL code 18 any thoughts?

[nikey22]

Hi guys,

I just finished reinstalling my OEM exhaust and I get a CEL, pulled the code and it is one long, and eight short ones... I believe this is code 18.

Anyone come across this? thanks

 

[4AU4LIFE]

I thought a code would be displayed as the CEL light flashing 'X' number of times, a pause, then 'X' number of times again and that would be the code.
Regardless, what year is your car?

 

[pgilliam1]

Code 18 (when pulled from the Srevice Check Connector) suggests "Ignition Timing Adjuster". Try a search on that.

 

[Larry Bastanza]

First thing I would do is pull the clock fuse and see if it comes back.

Regards,
LarryB

 

[nikey22]

update:

well, one long flash is equivalent to a "10"... and then 8 short flashes is equivalent to a "8". So together that's 18.

I did a couple of things:

Yes, this is the idler control circuit, but before doing anything I'm going to do exactly what Larry suggested, clear the code (pulled 7.5amp clock fuse) and run the car again. Interesting to note, this code came on after I hit a small bump on the road... anyways, will keep you posted on this.

Also, the other lights didn't flash (TCS) or (ABS) lights, so I think there are no issues with those subsystems...

I'll keep you posted...

 

[jaja]

Bringing this back from the dead.

I've had CEL 18 in my 1991 for a while. It had been fairly intermittent and I didn't worry about it much. However, it has now been coming on during the test drive after resetting my ECU.

I've followed all of the troubleshooting steps as found in 11-60 of the 1991 service manual. Everything seems good (all voltages & resistances are within the specified ranges). Now, I'm at the point where I need to connect an ECU test harness for a final voltage check to see if there's an open/short or if my ECU is the problem.

Any more advice from the NSX gurus? Or has anyone else run into CEL 18?

My understanding is that the ignition timing adjuster is only really doing something at idle. However, even with the CEL on, my idle seems rock solid at ~750 RPM.

I've got a track day scheduled for tomorrow, the car drives well, idles well, am I OK to hit the tarmac?

Also, if anyone in the southern Ontario area has a ECU test harness that I could borrow to put this CEL to rest, please let me know!

Thanks,

Lucas