STUCK! Infamous "Reduced Engine Power" message
Thread Starter
1st Gear
Joined: Nov 2020
Posts: 1
Likes: 0
STUCK! Infamous "Reduced Engine Power" message
Hello all,
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Hello all,
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,600
Likes: 4,059
From: Cape Coral, Florida
Sounds like another serial data bus issue...if any module (BCM, PCM, HVAC) loses power or ground that power or ground needs to find “its way home” and that’s via your serial data wire and when that happens you’ll get all those DIC warnings plus you’ll see your gas gauge go to E and your water temp gauge maxes out...you also have a lot of U codes which are communication DTC’s...I’d have to look at your wiring and see what modules are powered from the IP fusebox !!...Oh, and welcome to the Forum !!
Last edited by C5 Diag; Nov 9, 2020 at 12:06 PM.
Cruising
Joined: Oct 2004
Posts: 13
Likes: 4
From: Weymouth Massachusetts
Hello all,
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
I have a 2000 C5 that sporadically throws up the infamous "Reduced Engine Power" warning as well as every other warning you could think of. Often when this happens the power windows and power doors also stop working, as does my keyless entry, AC, and ability to open the hatch.
I swapped the battery as I heard low voltage could cause this and have also cleaned all ground wires. I pulled my passenger fuse box today to search for loose or open wires but had no luck.
I can get the problem and messages to go away temporarily by pushing down on the passenger fuse box, but this fix only lasts a week or so (or until I hit a decent-sized bump). This leads me to believe it should be a loose or open wire.
I heard it could be the ECM but I am not convinced that is my issue as, like I said, the issue goes away by simply putting a little pressure on my passenger fuse box.
I did try looking for different threads as I know this is a hot topic, but have had no luck as of yet...
Any thoughts or ideas would be greatly appreciated or if you could point me to a thread that would also be helpful.
Thanks in advance everyone!
Codes:
P1626H / U1301H / U1255H / U1096H / U1016H / U1064H / U1040H / U1083H / U1176H / U1160H / B2284H / U1300H / B0361HC / B0441HC
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,600
Likes: 4,059
From: Cape Coral, Florida
I have a friend that's been chasing the same problem for two years now. He has many of the same codes, but no current codes (all history). Just yesterday tech told him he might need a new RDCM because it wasn't communicating. If you find a fix please post it. If we do I will post as well. Good Luck
Advanced
Joined: Jul 2020
Posts: 85
Likes: 2
From: Tennessee
Sounds like another serial data bus issue...if any module (BCM, PCM, HVAC) loses power or ground that power or ground needs to find “its way home” and that’s via your serial data wire and when that happens you’ll get all those DIC warnings plus you’ll see your gas gauge go to E and your water temp gauge maxes out...you also have a lot of U codes which are communication DTC’s...I’d have to look at your wiring and see what modules are powered from the IP fusebox !!...Oh, and welcome to the Forum !!
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,600
Likes: 4,059
From: Cape Coral, Florida
No, each module has 1 serial data wire and ALL of those serial data wires come together at 2 splice packs near the BCM...you would be looking at a bad power or ground at any of those modules that might not be communicating !!...videos below for your info !!...the drivers door module has a connector inside the rubber boot when you open the door and that connector goes bad because that door is opened and closed many times.
Last edited by C5 Diag; Nov 13, 2020 at 06:48 PM.
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Advanced
Joined: Jul 2020
Posts: 85
Likes: 2
From: Tennessee
No, each module has 1 serial data wire and ALL of those serial data wires come together at 2 splice packs near the BCM...you would be looking at a bad power or ground at any of those modules that might not be communicating !!...videos below for your info !!...the drivers door module has a connector inside the rubber boot when you open the door and that connector goes bad because that door is opened and closed many times.
https://youtu.be/I6RALaUkneE
https://youtu.be/Qlb8dBhbp2g
https://youtu.be/I6RALaUkneE
https://youtu.be/Qlb8dBhbp2g
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,600
Likes: 4,059
From: Cape Coral, Florida
First you would want a scan tool that will allow you to see all the modules...you can use a DVOM to troubleshoot (I use a scope and a CAN breakout box) to see if you have either 12 volts or ground on the serial data wire which is pin 2 on the DLC (where you hook up your scan tool to)...here is another good video below !!
Melting Slicks
Joined: Sep 2008
Posts: 3,138
Likes: 802
From: Espanola New Mexico
The OP of this thread states that problem goes away for a week or so after he presses down on IP fuse block, could problem be something as simple as a loose/dirty connection of the main power cable at the fuse block?
Heel & Toe
Joined: Jul 2020
Posts: 21
Likes: 5
From: Rochester NY
I had this same issue.
check this following thread
https://www.z06vette.com/threads/red...indows.117419/
it fixed all of my electrical issues. Seriously. All of them. I never get reduced engine power. Or the infamous abs lights. ALL OF THEM WERE SOLVED.
check this following thread
https://www.z06vette.com/threads/red...indows.117419/
it fixed all of my electrical issues. Seriously. All of them. I never get reduced engine power. Or the infamous abs lights. ALL OF THEM WERE SOLVED.