Ignition problem, bad key, grounding issue, or something else?
For the past few weeks, whenever I try to start my 2000 coupe, the instrument panel flickers and the gauge needles flutter. The car won't start on the first try, even after leaving the key in the ON position for a moment.
Starting 2 days ago, things seem to have gotten worse. The instrument panel still flickers. The A/C works fine, and there's no dimming in the HVAC display. However, I'm now seeing:
solid check engine light
Service ABS
Low Voltage
Reduce Engine Power
Check Gauges(Not all simultaneously, but each warning has illuminated).
I have a total of 4 keys for my C5
My dad has 5th key (full-size OEM key) that seems to work fine. While the 3 spare keys with the small heads appear to have smaller resistors than the OEM key, most of them produce the same flickering of the dash and the numerous warnings. The key at the bottom of the picture won't even turn (wrong VATS code, maybe idk).
I've pulled codes, twice. These are the codes I got the 1st time:
C1278 H - Traction temporarily cut by PCM
C1281 H - Steering sensor uncorrelated
C1288 H - Steering position sensor circuit
B2282
B2283/2285/2265 H 12V power feed 1&2
B2284 H
U1016 H - Normal software function?
I took a video of codes today and yesterday. I can post if necessary.
Overall, could this be something like a bad ignition switch, keys with bad/incorrect resistors, a grounding issue, or something else?
Last edited by mattd04; Jul 27, 2021 at 06:57 PM.
Last edited by C5 Diag; Jul 27, 2021 at 07:20 PM.
I don't have a multimeter yet, but I'll be buying one in the next few days, before I start taking stuff apart.
I may still replace the ignition switch in a couple weeks, as I have a new switch coming, AND I'm researching how to fix a fallen mirror in my C5's HUD.
However, having used a different key today and starting the car 3 times, I have had NO flickering or warning lights, and the car has always started on the 1st attempt. It may just be my eyes, but the resistor on this particular key seems to be thicker/less worn than the others.
Very strange.
EDIT: Never mind. That key produces the same problem.
Last edited by mattd04; Aug 1, 2021 at 07:17 PM.
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The ignition switch has been replaced. When I started the car this AM, prior to replacing the ignition switch, (I don't know how else to describe it ( I could almost feel as pulsing or stuttering from the ignition switch). Now, it's gone, as well as the flickering instrument panel, and all the crazy warning lights.
Thank you all for your help. Here is a picture of the old switch. The contacts are clearly worn.












