Check Engine light flashes constantly
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
Check Engine light flashes constantly
Went to start up my car again today and I get the same results, starts and then stalls 2 seconds later. Except now if I try to give it gas, the check engine light flashes constantly until it dies. I checked for codes and there are none. Does this mean I have a bad ECM or something?
Le Mans Master
Joined: Jun 2001
Posts: 6,694
Likes: 3
From: Less Talk, More WOT | Houston TX
Are you trying to start the car with the top two ALDL connector ports jumped? Field service mode will make the ses light flash quickly. The only other time I've seen a check engine light flash that fast when the car was running, was when we drove my brothers WS6 to the shop with open headers, the light was blinking because no oxygen sensors were detected. I don't know if that is applicable to our c4s or not. When you pull the codes on your car, are you getting the code 12 (ecm ok) code?
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
car stalls
do you have a owner's manual? read where it says if it flashes, you have to get it fixed now!
ok, you have to pull codes to find out what's wrong.
A. use a paper clip, short out the two lower R/H pins in the plastic connector on the right side of your left dashboard right where your right knee is.
B. turn on the key, don't try to start the engine, and the check engine light will start flashing and the cooling fan will start running on it's own.
1. the check engine light will flash once then twice 2 times.
2. then start counting the flashes. like 3 flashes, a pause, then 4 flashes. that equals code 34
3. get all the codes written down, then it flashes once then twice 2 times. that means you are at the end of the codes. it will start all over again till you take out the jumper and turn off the key.
4. Buy a manual, even a haynes manual from autozone will have the list of codes.
welcome to the fuel injection part of your life.
ok, you have to pull codes to find out what's wrong.
A. use a paper clip, short out the two lower R/H pins in the plastic connector on the right side of your left dashboard right where your right knee is.
B. turn on the key, don't try to start the engine, and the check engine light will start flashing and the cooling fan will start running on it's own.
1. the check engine light will flash once then twice 2 times.
2. then start counting the flashes. like 3 flashes, a pause, then 4 flashes. that equals code 34
3. get all the codes written down, then it flashes once then twice 2 times. that means you are at the end of the codes. it will start all over again till you take out the jumper and turn off the key.
4. Buy a manual, even a haynes manual from autozone will have the list of codes.
welcome to the fuel injection part of your life.
Race Director
Joined: Jun 2004
Posts: 13,969
Likes: 710
From: WI
No codes, hmm it could be the computer. From people on here that have had trouble with them, it can be tough to tell without trying one. If you run a search there are a few topics on bad computers. I looked into that awhile ago since mine had some odd symtoms. Have you thought of getting one from a local place and trying it? If it doesn't help then you can return it.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by coupeguy2001
do you have a owner's manual? read where it says if it flashes, you have to get it fixed now!
ok, you have to pull codes to find out what's wrong.
A. use a paper clip, short out the two lower R/H pins in the plastic connector on the right side of your left dashboard right where your right knee is. The two UPPER R/H pins.
B. turn on the key, don't try to start the engine, and the check engine light will start flashing and the cooling fan will start running on it's own.
1. the check engine light will flash once then twice 2 times. Three times. All codes will flash 3 times, including code 12.
2. then start counting the flashes. like 3 flashes, a pause, then 4 flashes. that equals code 34
3. get all the codes written down, then it flashes once then twice 2 times. that means you are at the end of the codes. it will start all over again till you take out the jumper and turn off the key. As I said above, three times.
4. Buy a manual, even a haynes manual from autozone will have the list of codes. A Haynes manual will probably identify what circuits the codes came in on, but you will need the FSM to properly trouble shoot the cause of the codes. A code for the EGR valve doesn't mean the EGR valve is bad, just that a malfunction occurred on the EGR circuit.
welcome to the fuel injection part of your life.
ok, you have to pull codes to find out what's wrong.
A. use a paper clip, short out the two lower R/H pins in the plastic connector on the right side of your left dashboard right where your right knee is. The two UPPER R/H pins.
B. turn on the key, don't try to start the engine, and the check engine light will start flashing and the cooling fan will start running on it's own.
1. the check engine light will flash once then twice 2 times. Three times. All codes will flash 3 times, including code 12.
2. then start counting the flashes. like 3 flashes, a pause, then 4 flashes. that equals code 34
3. get all the codes written down, then it flashes once then twice 2 times. that means you are at the end of the codes. it will start all over again till you take out the jumper and turn off the key. As I said above, three times.
4. Buy a manual, even a haynes manual from autozone will have the list of codes. A Haynes manual will probably identify what circuits the codes came in on, but you will need the FSM to properly trouble shoot the cause of the codes. A code for the EGR valve doesn't mean the EGR valve is bad, just that a malfunction occurred on the EGR circuit.
welcome to the fuel injection part of your life.
RACE ON!!!
Drifting
Joined: Jun 2002
Posts: 1,945
Likes: 41
From: Corinth TX
I'm betting it's bad gas. You can always get a little sample by going to the fuel rail and getting a sample from the fuel pressure schrader valve. bad gas may be a long shot but hey, it turned out to be one of my problems. Well my car's problem not mine.
Thread Starter
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
Nope, I checked it today. No leaks of any kind and its getting fuel just fine. Just got fuel roughly 2 weeks ago and ran fine for the first half tank, still sitting at half tank.
Anyway, my bud looked at it and thinks it could be a bad alternator. Seeing as how the battery is new along with plugs, wires, etc. I could see that. I dont know when the alternator was last replaced. I know that if I keep feathering the gas eventually it will stay running just fine once warmed up. Is it worth having it checked?
Anyway, my bud looked at it and thinks it could be a bad alternator. Seeing as how the battery is new along with plugs, wires, etc. I could see that. I dont know when the alternator was last replaced. I know that if I keep feathering the gas eventually it will stay running just fine once warmed up. Is it worth having it checked?
