No Start
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
No Start
A while back i posted about no start issue and no communication issue, most of the no communication issues was solved with new battery, but i am still left with the no start, no communication with PCM and U1255 H C code wich is Serial Data Line Malfunction in the BCM section.
When i say no start i mean the engine is turning over but no fire.
Any help would be much appreciated.
When i say no start i mean the engine is turning over but no fire.
Any help would be much appreciated.
Tech Contributor
Joined: Jan 2007
Posts: 19,417
Likes: 1,144
From: Dyer, IN
A while back i posted about no start issue and no communication issue, most of the no communication issues was solved with new battery, but i am still left with the no start, no communication with PCM and U1255 H C code wich is Serial Data Line Malfunction in the BCM section.
When i say no start i mean the engine is turning over but no fire.
Any help would be much appreciated.
When i say no start i mean the engine is turning over but no fire.
Any help would be much appreciated.
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
I checked current codes and it showing no communication for the PCM and on the BCM it's showing U1255 H C Serial Data Line Malfunction.
Fuel i am not getting any fuel pressure and i am not hearing the pump could that be from the PCM? How do i check for spark?
Also i checked the connection for the PCM and the BCM they are all tight and clean when i unplugged them to check.
Fuel i am not getting any fuel pressure and i am not hearing the pump could that be from the PCM? How do i check for spark?
Also i checked the connection for the PCM and the BCM they are all tight and clean when i unplugged them to check.
Tech Contributor
Joined: Jan 2007
Posts: 19,417
Likes: 1,144
From: Dyer, IN
I checked current codes and it showing no communication for the PCM and on the BCM it's showing U1255 H C Serial Data Line Malfunction.
Fuel i am not getting any fuel pressure and i am not hearing the pump could that be from the PCM? How do i check for spark?
Also i checked the connection for the PCM and the BCM they are all tight and clean when i unplugged them to check.
Fuel i am not getting any fuel pressure and i am not hearing the pump could that be from the PCM? How do i check for spark?
Also i checked the connection for the PCM and the BCM they are all tight and clean when i unplugged them to check.
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
The car sat at the shop for 4 months that's why i took the car a way from them and told them that any thing will cost me on getting the car running i will back charge them. I tried contacting Chevy dealer and they wouldn't take the car in since it's an American specs not a gulf specs car
So at this point i just need to get the car running at any cost and i need all the help i can get from my brothers at the forums to troubleshoot this issue.
Tech Contributor
Joined: Jan 2007
Posts: 19,417
Likes: 1,144
From: Dyer, IN
Yes the car was at the shop after an accident, the damage was undercarriage so the shop has to separate the body from the drive terrain to fix the damage. I am thinking some grounds or some connection not being plugged in what's causing the issue.
The car sat at the shop for 4 months that's why i took the car a way from them and told them that any thing will cost me on getting the car running i will back charge them. I tried contacting Chevy dealer and they wouldn't take the car in since it's an American specs not a gulf specs car
So at this point i just need to get the car running at any cost and i need all the help i can get from my brothers at the forums to troubleshoot this issue.
The car sat at the shop for 4 months that's why i took the car a way from them and told them that any thing will cost me on getting the car running i will back charge them. I tried contacting Chevy dealer and they wouldn't take the car in since it's an American specs not a gulf specs car
So at this point i just need to get the car running at any cost and i need all the help i can get from my brothers at the forums to troubleshoot this issue.
Check your engine grounds. Start with G106.
http://forums.corvetteforum.com/c5-t...e-grounds.html
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Tech Contributor
Joined: Jan 2007
Posts: 19,417
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From: Dyer, IN
G106, above the starter: 1 terminal = black battery cable, 1 terminal smaller black wire
G105, lower left/rear of block. 1 terminal = braided wire to frame rail, 1 terminal smaller black wire.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
Update
OK i got to feeling around today and found G105 is connected to the driver side of the block, G106 is connected where it should be, but i found a small ground wire is connected to the starter with the two red wires, this grond is brooken off from the connector. Could that be the mystery ground that causing all the no start and PCM no communication issues?
Another issue i discovered is that when i put the ignition on the on position there's a grey relay buzzing in the fuses box under the hood, but when i try to crank the car it stops buzzing. Could that be from this mystery ground also? When i checked that relay it says ignition relay.
Another issue i discovered is that when i put the ignition on the on position there's a grey relay buzzing in the fuses box under the hood, but when i try to crank the car it stops buzzing. Could that be from this mystery ground also? When i checked that relay it says ignition relay.
Last edited by 99MALLETT396; Sep 1, 2011 at 12:12 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,417
Likes: 1,144
From: Dyer, IN
There is NO Ground wire to the starter. You say G106 is connected, but again, there should be two terminals...one small, and one large from the battery.
There should be a total of three wires on the large post of the solenoid: Red, rust, and grey.
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
You say the grounds are connected.....but......are the appropriate number of wires at each ground?
There is NO Ground wire to the starter. You say G106 is connected, but again, there should be two terminals...one small, and one large from the battery.
There should be a total of three wires on the large post of the solenoid: Red, rust, and grey.
There is NO Ground wire to the starter. You say G106 is connected, but again, there should be two terminals...one small, and one large from the battery.
There should be a total of three wires on the large post of the solenoid: Red, rust, and grey.
The G106 is connected with two terminals the small and the big one comming from the battery.
There's three wires connected to the starter solenoid, but the small one is broken from the terminal, could this be the wire that causing everything?
But the thing that i don't get is why when i put the ignition on the on position i get one grey relay buzzing under the hood and all the coils are firing? Then when i try to crank the car the buzzing relay stops buzzing and the coils stops firing? When i checked what's that relay's for it, it's saying it's for ignition.
Tech Contributor
Joined: Jan 2007
Posts: 19,417
Likes: 1,144
From: Dyer, IN
Yes the appropriate number of wiers are at each ground.
The G106 is connected with two terminals the small and the big one comming from the battery.
There's three wires connected to the starter solenoid, but the small one is broken from the terminal, could this be the wire that causing everything?
But the thing that i don't get is why when i put the ignition on the on position i get one grey relay buzzing under the hood and all the coils are firing? Then when i try to crank the car the buzzing relay stops buzzing and the coils stops firing? When i checked what's that relay's for it, it's saying it's for ignition.
The G106 is connected with two terminals the small and the big one comming from the battery.
There's three wires connected to the starter solenoid, but the small one is broken from the terminal, could this be the wire that causing everything?
But the thing that i don't get is why when i put the ignition on the on position i get one grey relay buzzing under the hood and all the coils are firing? Then when i try to crank the car the buzzing relay stops buzzing and the coils stops firing? When i checked what's that relay's for it, it's saying it's for ignition.
Thread Starter
Racer
Joined: Jun 2005
Posts: 469
Likes: 2
From: Qatif
The broken small wire at the starter is a dark color wire that's why i thought it's a ground. I will verify the color at G106 and get back to you, but i sure there's a black ground wire coming from the battery to the pass side of the block withe the small wire that's coming from the harness.
Any thoughts on the relay issue?
Any thoughts on the relay issue?