TT not starting no power supply to ECU?
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TT not starting no power supply to ECU?
Hi there.
New member here. My name is jamie from rotherham south yorkshire.
I have a 1999 V plate TT i baught cheap from a friend of mine as a non runner.
My problem is i seam to have no power supply to the ECU ir what i think!
I checked my fuel pump relay under the drivers dash pannel and other two relays under the bonnet on the right side (standing at the front of the car) of the bulk head all are working fine and contacts inside are very clean and if i click the fuel pump relay in it sends fuel direct to the fuel rail BUT on ignition not one of the relays are clicking to make up the circuit in order to start. Also no fuel is delivered to the fuel rail. Theres power to the relays and power to the injectors and power to the coil pack but still dosent start when i crank the car over. Also there is no engine management light lighting up on the dashboard when the ignition is turned on giving me the idea the ECU is not powering up? Just to note inhave checked all fuses on the drivers side fuse box and all are ok. Does anyone have any ideas what i could try next or have i missed anything that may need testing or checking? Next option is to have a look at the ECU and is their another relay in with the ECU inside the protective plastic box under the windscreen?
Thank you all in advance for any help
New member here. My name is jamie from rotherham south yorkshire.
I have a 1999 V plate TT i baught cheap from a friend of mine as a non runner.
My problem is i seam to have no power supply to the ECU ir what i think!
I checked my fuel pump relay under the drivers dash pannel and other two relays under the bonnet on the right side (standing at the front of the car) of the bulk head all are working fine and contacts inside are very clean and if i click the fuel pump relay in it sends fuel direct to the fuel rail BUT on ignition not one of the relays are clicking to make up the circuit in order to start. Also no fuel is delivered to the fuel rail. Theres power to the relays and power to the injectors and power to the coil pack but still dosent start when i crank the car over. Also there is no engine management light lighting up on the dashboard when the ignition is turned on giving me the idea the ECU is not powering up? Just to note inhave checked all fuses on the drivers side fuse box and all are ok. Does anyone have any ideas what i could try next or have i missed anything that may need testing or checking? Next option is to have a look at the ECU and is their another relay in with the ECU inside the protective plastic box under the windscreen?
Thank you all in advance for any help
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I having the exact same thing here up in scotland with a 1999 model. I've checked everything I can think of. Have you tried a diagnostics tool? I'm not getting any connection to ecu but it connects too abs and airbag units okay.
I'm seriously about to scrap mine. 4 weeks its been off the road. Just wouldn't start one morning.
How do we find out if its in crash mode (immobilized)
Regards
Darren
I'm seriously about to scrap mine. 4 weeks its been off the road. Just wouldn't start one morning.
How do we find out if its in crash mode (immobilized)
Regards
Darren
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Did you ever figure out the issue? My 2001 roadster has the same issue but is intermittent and usually have when trying to start it in the morning, but I've been driving dow n the freeway and will lose all power..
I was thinking its a bad ECU, but haven't been able to narrow it down..
-john
I was thinking its a bad ECU, but haven't been able to narrow it down..
-john
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Fix
Hi, yes I managed to fix the problem. Sorry I thought I had updated the forum.
Basically I was going to jump the main power to the ecu straight from the battery so to do do had to strip some of the black tape from the ecu connectors, looking straight at it from the front of car its the connector on the left.
I started stripping this back, maybe 8 inches to find the correct live wire and there it was, a corroded broken wire. It seems Audi used a plastic connector to allow 2 wires to become one wire and over time the plastic decayed, like an old rubber elastic band.
Reconnected, soldered, wrapped back up, Vedder started and ran prefect.
I reckon every tt of a certain age will develop this fault at some point.
Basically I was going to jump the main power to the ecu straight from the battery so to do do had to strip some of the black tape from the ecu connectors, looking straight at it from the front of car its the connector on the left.
I started stripping this back, maybe 8 inches to find the correct live wire and there it was, a corroded broken wire. It seems Audi used a plastic connector to allow 2 wires to become one wire and over time the plastic decayed, like an old rubber elastic band.
Reconnected, soldered, wrapped back up, Vedder started and ran prefect.
I reckon every tt of a certain age will develop this fault at some point.
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Is this still active
I have been having what sounds like the same issue on a 2010 a4 s line .... I will put the key in 1st position then when I click second position to begin starting the engine the coil light stays on the car will only start on occasion when I keep trying and get it when the coil light goes off. There is 9 clicks from the ecu but I have noticed on my obd app it says no connection to ecu until that light goes out... and also the car started 1st try the other day while hooked up to another car so it sounds roughly the same issue....
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