Lovethybeard96

Hey guys what's up? I'm new to the site but not new to the cars lol. I just recently got another one. It's a 96 z28 LT1 with the 6 speed transmission. I went to get it inspected and it threw 4 codes that failed me. 3 of the codes were O2 sensor codes it has long tube headers with the sensors plugged in but no rear O2 sensors so I ordered Sims to go back there and replaced the one bad one up front. The code that's kicking me in the FACE is the P1661 coded for MIL circuit. My check engine light doesn't come on at all. When I turn the key to on position it doesn't illuminate. I took apart the dash and got the cluster out and checked the bulb it's fine. I've traced down the brown/white wire that is the circuit wire for the light and I can't find any cuts, nicks, shorts or anything in the wire. I've unbolted the PCM under the hood and unplugged the Blue harness and I think I grounded the wire correct with another wire with my nephew in the car to turn the key to on position and tell me if light comes on and nothing. I'm stumped haha I cannot figure it out. I'm hoping it's a bad cluster because I need to pass inspection but can't with this code. If anyone has any idea or anything I'd love to hear it!

Thanks in advance guys!

Lovethybeard96

Nobody has any info? I know I explained it in enough detail.

Injuneer

Do you have access to the 1996 factory service manual? If not, these are the two pages for P1661. I didn't see anywhere that you verified 12V to the bulb socket.

Since you are new, let me introduce us. This used to be a huge site, very active. At this point, the only action is really the LT1 topics, and we have a handful of very knowledgeable people who can usually help you out. We do ask your patience, since with the limited number of "regulars", it may take a while for someone to read and respond to your post. Hopefully you understand.

GaryDoug

Make sure a previous owner hasn't swapped the instrument cluster bulbs (and The MIL) with LED's, because that would set the code.

If all else fails, you can put a 1000 Ohm resistor (or a small light bulb) from the brn/wht wire to +12 v and the code should disappear.

Lovethybeard96

I checked the bulbs in the cluster they are the original type bulbs no LED. I knew the bulb on the break light in the dash worked so I switched the SES bulb and the break light bulb and it still didn't work. I mayou just have to wire it straight to a 12v source.

Injuneer

All the notification lights (SES, AIRBAG, LOW TRAC, BRAKE, LOW COOLANT, SKIP SHIFT, ASR) get power from fuse #9. I would assume its a printed circuit board, so the inability to turn the light on could be due to:

-broken conductor on board for that specific socket

-damaged pins in socket

-not receiving ground on the brown/white wire. That leaves the possibility of a damaged pin on the cluster connector, damaged pin on connector C230, damaged pin at the PCM (which you appear to have already checked), and a break in the wire from the PCM to C230, or the wire from C230 to the cluster connector.

Gary.... please correct anything wrong with the above.

Lovethybeard96

Yes I checked at the PCM blue connector and pin #9 if I'm not mistaken. All other lights on the instrument cluster work so it's not the fuse. I believe it's something to do with the cluster as you said a broken conductor or damaged pin. I traced the brn/Wht wire to the C230 plug in the passenger kick panel and it was good and there ton the pcm through the firewall and saw nothing out of the ordinary. I'll get out my multimeter and check it hot. I grounded pin 9 in the blue pcm harness and the light did not come on then. I'll run back over the wire from the cluster back to the PCM again just to check again.

Lovethybeard96

This is my first LT1 camaro. I've owned a 2000 SS with the LS1 but never had any electrical problems. Other then those two I've owned and restored an 80 Z28 and two 92 RS which I swapped in 383 strokers I built myself. I know my way around a Gen 1 SBC just nothing like what I have now. The electronics throw me off.