04 Suburban Cluster Issue

[TylerHagerdorn]

Hey Y'all.

I had a faulty cluster in my 04 Burb, the fuel gauge would randomly drop to dashes on the range screen. And then when you hit the gas pedal and gave it decent throttle, at an idle, the gauge would come back to life. I chalked it up to a bad cluster since these are so notorious for going bad.

However I purchased a fully rebuilt one from ISS, which I've heard nothing but good things about. I put it in Wednesday, and it seemed to be functioning properly minus the DIC screen being very dim. I contacted them and they've sent me another one I'll receive Tuesday.

The issue started again today with the new cluster going to dashes with the low fuel light on the dash, and jumping back up when giving it throttle at an idle. Smacking the dash does nothing to make it respond...only hitting the throttle does. When driving it seems perfectly fine.

So my question now is, why is the fuel gauge going to dashes on the range and going back up when throttle is applied? This is my 4th GMT800 and the first one I've had these cluster issues with. Could the plug for the cluster have loose pins not giving it solid contact? I've been on alldata and got all the wiring diagrams for the cluster and all that and traced wires, minus to the fuel pump because I can't drop the tank on th ground due to my health. But the truck starts fine every single time. No CEL.

I'm absolutely lost. This is so strange. Any help or advice would be so appreciated. Thank you

 

[strutaeng]

What do you mean the fuel to dashes on the range?

The fuel gauge needle drops to empty? That could be the fuel pump sender.

I have a 2004 project suburban that I hadn't driven in a while that started doing that. The needle dropped to zero and the low fuel light would come one. There was also a U-code. If I cleared the code it would do it again in a few seconds. Sometimes it would read correctly intermittently. I think it was a stuck sender. I drive it around and seems like the problem went away. It may also be a wiring issue.

 

[Ibustbravo]

Hey Y'all.

I had a faulty cluster in my 04 Burb, the fuel gauge would randomly drop to dashes on the range screen. And then when you hit the gas pedal and gave it decent throttle, at an idle, the gauge would come back to life. I chalked it up to a bad cluster since these are so notorious for going bad.

However I purchased a fully rebuilt one from ISS, which I've heard nothing but good things about. I put it in Wednesday, and it seemed to be functioning properly minus the DIC screen being very dim. I contacted them and they've sent me another one I'll receive Tuesday.

The issue started again today with the new cluster going to dashes with the low fuel light on the dash, and jumping back up when giving it throttle at an idle. Smacking the dash does nothing to make it respond...only hitting the throttle does. When driving it seems perfectly fine.

So my question now is, why is the fuel gauge going to dashes on the range and going back up when throttle is applied? This is my 4th GMT800 and the first one I've had these cluster issues with. Could the plug for the cluster have loose pins not giving it solid contact? I've been on alldata and got all the wiring diagrams for the cluster and all that and traced wires, minus to the fuel pump because I can't drop the tank on th ground due to my health. But the truck starts fine every single time. No CEL.

I'm absolutely lost. This is so strange. Any help or advice would be so appreciated. Thank you

I had to laugh at your smacking the dash, been there.. This has to be a ground or power issue. Can you chart/log and build histograms for your alternator power output and other stuff? There's a lot of tools out there, I use HP tuners. Autoenguinety is another.. I don't like their logging though.

I found an issue with my 07 F350 by accident while chasing another issue. I was logging for tuning issues and included the power output.. I found after 15-20 min the alternator regulator output would go to 15-16 volts.. The dash would go dead; sometimes, and the engine would always act up. I'd have never found it with a meter because it wouldn't do it sitting in the driveway.

 

[TylerHagerdorn]

I had to laugh at your smacking the dash, been there.. This has to be a ground or power issue. Can you chart/log and build histograms for your alternator power output and other stuff? There's a lot of tools out there, I use HP tuners. Autoenguinety is another.. I don't like their logging though.

I found an issue with my 07 F350 by accident while chasing another issue. I was logging for tuning issues and included the power output.. I found after 15-20 min the alternator regulator output would go to 15-16 volts.. The dash would go dead; sometimes, and the engine would always act up. I'd have never found it with a meter because it wouldn't do it sitting in the driveway.

I think we've all been there smacking the dash lol. I only did it because I know other people have had to do it, so I wanted to see if that made something happen. But nope. Just hitting the throttle was the only thing that caused the fuel gauge to jump back to life. And this is a fully rebuilt cluster by one of the best companies doing them.

I checked the grounds at the bases of the a pillars the other day when I had the top of the dash off, and they are good. Didn't see any issues there. Everything else in the truck works as it should. I put the correct alternator on it, as the previous owner put the 105a when the RPO code calls for the 145a since my truck is loaded. That's all good now. And I did that over a month ago.

What I'm thinking is the cluster connector has loose pins. Because there's been clusters in and out and in and out of this truck. The PCM is what sends the "DIC Fuel Signal" and the "Fuel Level Signal" to the cluster. And it does go through a couple connectors on the way from the PCM. So I have all the diagrams printed and I'm going to try and make myself a simplified diagram of where it goes so I can check that too.

I also know the fuel pump is grounded through the frame under the driver's door. It looks good on the outside but I haven't pulled it off to check the other side of the eyelet. Which I'll do today because I have to replace the column shift mechanism as it's loosey goosey. So I'll cover all my bases then too.

I have a connector from a truck that never had the cluster removed until it was sold, looks and appears to be much tighter but I'm not going to wire that in until I get the replacement cluster on Tuesday.

 

[Foot0069]

I think we've all been there smacking the dash lol. I only did it because I know other people have had to do it, so I wanted to see if that made something happen. But nope. Just hitting the throttle was the only thing that caused the fuel gauge to jump back to life. And this is a fully rebuilt cluster by one of the best companies doing them.

I checked the grounds at the bases of the a pillars the other day when I had the top of the dash off, and they are good. Didn't see any issues there. Everything else in the truck works as it should. I put the correct alternator on it, as the previous owner put the 105a when the RPO code calls for the 145a since my truck is loaded. That's all good now. And I did that over a month ago.

What I'm thinking is the cluster connector has loose pins. Because there's been clusters in and out and in and out of this truck. The PCM is what sends the "DIC Fuel Signal" and the "Fuel Level Signal" to the cluster. And it does go through a couple connectors on the way from the PCM. So I have all the diagrams printed and I'm going to try and make myself a simplified diagram of where it goes so I can check that too.

I also know the fuel pump is grounded through the frame under the driver's door. It looks good on the outside but I haven't pulled it off to check the other side of the eyelet. Which I'll do today because I have to replace the column shift mechanism as it's loosey goosey. So I'll cover all my bases then too.

I have a connector from a truck that never had the cluster removed until it was sold, looks and appears to be much tighter but I'm not going to wire that in until I get the replacement cluster on Tuesday.

Have you thought of pulling the pins and tightening them up. I've one of these and find it very handy.

Advance Auto Parts - Down for Maintenance

 

[Foot0069]

A lot easier than wiring in a new plug

 

[Fless]

I'd recommend cleaning the grounds that are on the body mount, just under the driver's door hinges (right behind the left front tire). There will be two or three wires on two bolts, and one is the TBCM ground.

I'd also pull the two PCM connectors and check for water intrusion and pin fitment. The gaskets can leak and water can sit in the lower part of the connector.

It'll be interesting to see what you find to be the cause.

 

[Ibustbravo]

I think we've all been there smacking the dash lol. I only did it because I know other people have had to do it, so I wanted to see if that made something happen. But nope. Just hitting the throttle was the only thing that caused the fuel gauge to jump back to life. And this is a fully rebuilt cluster by one of the best companies doing them.

I checked the grounds at the bases of the a pillars the other day when I had the top of the dash off, and they are good. Didn't see any issues there. Everything else in the truck works as it should. I put the correct alternator on it, as the previous owner put the 105a when the RPO code calls for the 145a since my truck is loaded. That's all good now. And I did that over a month ago.

What I'm thinking is the cluster connector has loose pins. Because there's been clusters in and out and in and out of this truck. The PCM is what sends the "DIC Fuel Signal" and the "Fuel Level Signal" to the cluster. And it does go through a couple connectors on the way from the PCM. So I have all the diagrams printed and I'm going to try and make myself a simplified diagram of where it goes so I can check that too.

I also know the fuel pump is grounded through the frame under the driver's door. It looks good on the outside but I haven't pulled it off to check the other side of the eyelet. Which I'll do today because I have to replace the column shift mechanism as it's loosey goosey. So I'll cover all my bases then too.

I have a connector from a truck that never had the cluster removed until it was sold, looks and appears to be much tighter but I'm not going to wire that in until I get the replacement cluster on Tuesday.

Haha.. This about sums it up? This damned truck!

 

[TylerHagerdorn]

I'd recommend cleaning the grounds that are on the body mount, just under the driver's door hinges (right behind the left front tire). There will be two or three wires on two bolts, and one is the TBCM ground.

I'd also pull the two PCM connectors and check for water intrusion and pin fitment. The gaskets can leak and water can sit in the lower part of the connector.

It'll be interesting to see what you find to be the cause.

Cleaned the grounds very well yesterday. Didn't change a thing. This truck surprisingly is not rotted out like most of the other ones in Ohio.

I got my second replacement cluster and the DIC is still not as bright as my last truck. But the thing that's absolutely pissing me off and making me want to rip my head off, is the fuel gauge...sitting at an idle it will just move up and down and up and down and up and down...my three other trucks never did that constantly. If you drove and then parked it might drop a few miles on the range display and then come back up. But I always knew what my fuel level is.

These refurbished clusters are doing the same thing the one in my truck was doing. I don't freaking get it. I've tested the fuel level sensor wiring at the PCM, at the connector under the fuse box and it's all good. Truck fires up every single time without issue so I do not suspect a fuel pump issue.

The gauge gets the level from the PCM, not directly from the fuel pump.

 

[TylerHagerdorn]

Pulled the PCM connectors and found like oil looking shit inside the PCM and all over the connectors. It didn't smell like oil but I don't know where it came from

I'd recommend cleaning the grounds that are on the body mount, just under the driver's door hinges (right behind the left front tire). There will be two or three wires on two bolts, and one is the TBCM ground.

I'd also pull the two PCM connectors and check for water intrusion and pin fitment. The gaskets can leak and water can sit in the lower part of the connector.

It'll be interesting to see what you find to be the cause.