C5 Z Injector Faults/Random Missfire Issues
Thread Starter
Instructor
Joined: Feb 2011
Posts: 130
Likes: 8
From: Memphis TN
C5 Z Injector Faults/Random Missfire Issues
My C5 Z sat up most of the Winter and didn't get ran hardly at all. I didn't have it on a battery tender and it killed the old battery too many times. When I jumped it off this Spring, it ran like crap and was giving me codes for "charge system fault" along with some other codes. I replaced the battery, but that didn't totally fix the issues.
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
1/4 mile/AutoX
Joined: Jun 2014
Posts: 11,442
Likes: 2,189
From: Buffalo Texas
My C5 Z sat up most of the Winter and didn't get ran hardly at all. I didn't have it on a battery tender and it killed the old battery too many times. When I jumped it off this Spring, it ran like crap and was giving me codes for "charge system fault" along with some other codes. I replaced the battery, but that didn't totally fix the issues.
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
My C5 Z sat up most of the Winter and didn't get ran hardly at all. I didn't have it on a battery tender and it killed the old battery too many times. When I jumped it off this Spring, it ran like crap and was giving me codes for "charge system fault" along with some other codes. I replaced the battery, but that didn't totally fix the issues.
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
When idling (with a/c off) it runs pretty smooth and doesn't throw a CEL. Once you put a load on it in any way (turn the a/c on or put it in gear) it trips a CEL. I cleared the codes, but the ones that keep coming back for the PCM are P0155 (02 sensor heater bank malfunction), P0200 (injector circuit malfunction), and P0300 (random Missfire) There are also 3 codes for BCM that won't clear, although I'm not sure if they are related: B0502, B0507, and B2482 (DRL and backup lamp relay circuits).
I went ahead and ran all the BG fuel treatments for cleaning the fuel system and injectors, as well as to try and to somewhat restore the fuel just in case the old fuel is part of the problem. I'm now starting to think that this may be an issue with the voltage regulator. Does that seem feasible? If so, is the voltage regulator in this system built into the alternator?
Thread Starter
Instructor
Joined: Feb 2011
Posts: 130
Likes: 8
From: Memphis TN
What else would cause injector circuit issues? The car ran fine before the battery died completely for the last time. Ever since then, it's had these codes that persist. I have a tune in it that is supposed to tell it to ignore the cats, which is weird that one of the codes is for an 02. I thought maybe the tune in the PCM became corrupted when it was discharged for that long so I reflashed the tune in. This still didn't fix the issues though. Since it's not throwing a code for a particular bank, it's hard to pinpoint if it's actually and injector or coil pack. Plugs are only about a year old so they should be good.
Safety Car
Joined: Mar 2016
Posts: 3,534
Likes: 432
From: Atlantic Beach FL.
When the voltage gets low the car will start throwing codes like crazy. If that isn't the problem, you could check the wiring connections and grounding points. Mine had bad wiring. The insulation on the individual wires was literally peeling off.
Thread Starter
Instructor
Joined: Feb 2011
Posts: 130
Likes: 8
From: Memphis TN
Yes, when the voltage got low, it started throwing these crazy codes, but never before. Wiring seems ok at first glance. The codes keep coming bask though and there is a miss. What are some things that would cause the injector circuit issue?
Last edited by Mr. Sinister; Jun 13, 2016 at 08:11 PM.
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
The P0200 sets when the voltage to one or more injectors is out of range. This in turn sets the misfire code. The diagnostic table in the manual is about 20 steps and requires a tech 2 for the tests. All of the tests are designed to test for problems with the wiring and connections. Start with a simple test light and see if you can identify the injector or injectors that are not firing. The problem could be anywhere from the pcm to the injector itself. First step is to see which one or ones have a problem and then carefully check the wires and connectors, esp harness terminal and at the pcm. Where was the car stored for the winter, rodents have been known to do extensive damage to wiring. There are also fuses for the injectors you could check. The location for these can be found in your owners manual. If you are good with a dmm there are other tests you can do without a tech 2.
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Thread Starter
Instructor
Joined: Feb 2011
Posts: 130
Likes: 8
From: Memphis TN
I have a tune that ignores the front 02 sensors because I have no cats, yet one of the codes is for an 02 sensor that keeps coming up. Even though it's not looking for the fronts, if I have a bad rear 02 will it cause these issues?
Drifting
Joined: Feb 2008
Posts: 1,596
Likes: 67
From: Bahama North Carolina
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 481
From: OK
The P0200 sets when the voltage to one or more injectors is out of range. This in turn sets the misfire code. The diagnostic table in the manual is about 20 steps and requires a tech 2 for the tests. All of the tests are designed to test for problems with the wiring and connections. Start with a simple test light and see if you can identify the injector or injectors that are not firing. The problem could be anywhere from the pcm to the injector itself. First step is to see which one or ones have a problem and then carefully check the wires and connectors, esp harness terminal and at the pcm. Where was the car stored for the winter, rodents have been known to do extensive damage to wiring. There are also fuses for the injectors you could check. The location for these can be found in your owners manual. If you are good with a dmm there are other tests you can do without a tech 2.
C5 battery charge loss chart
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Go have your battery LOAD tested...
Last edited by 73Corvette; Jul 4, 2016 at 07:00 AM.
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Have you given your injector wiring harness a serious CLOSE inspection? Especially near the firewall area where it makes a turn to join the engine harness? The OE fuel rail stop brackets have sharp edges and there are instances of the harness chaffing against it.
Same goes for your coil wire harness.
Same goes for your coil wire harness.
Pro
Joined: May 2014
Posts: 670
Likes: 46
From: Indiana
If you have no cats you should have a tune that ignores the rear o2 sensors, not the fronts. Front o2 sensors are used when running in closed loop fueling.
Thread Starter
Instructor
Joined: Feb 2011
Posts: 130
Likes: 8
From: Memphis TN
GET a NEW battery and FULLY charge it... you might surprised at how many issues this resolves...
C5 battery charge loss chart
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Go have your battery LOAD tested...
C5 battery charge loss chart
A fully charged battery should be 12.6v or more.
If the battery is
12.5 = 85% charged
12.4 = 65%
12.3 = 50%
12.2 = 35%
12.1 = drained
Go have your battery LOAD tested...
Maybe it ignores the rears. Whatever is normal. I've been running this tune for 3 years with no issues until the battery went totally dead.