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Immobiliser problems (Yellow key code light)

28K views 19 replies 12 participants last post by  botasky 
#1 ·
My 156 is giving me intermittant starting problems as follows. Every so often when i turn the key to start the engine it turns over but after 5 or 6 seconds fails to fire and start up. If i return the key to stop and try it again it always starts. The weather is nothing to do with it as this morning it started first time after being out in the rain all night. I have made several journeys today which involved starting the car 5 or 6 times throughout the day with no problems at all. However tonight it failed to start at the first attempt but did start at the second attempt. This has been happening for several weeks. Some days the car will start first time all day. As previously stated if it does not start at the first attempt it does 100% at the second attempt. The battery is nearly new and will trying to start it you can hear there is loads of life in the battery. I spoke to Jamie at Alfaworkshop in Royston who asked me if the yellow key code light stayed on when i was having trouble starting. I told him i did not notice but will look at the key code symbol everytime i start up. Jamie said this light should only come on for a split second at start up and if it stays on it does not matter how long i try to start the car if this light stays on the car will never start. The yellow key code light apparently is the immobilser. When it failed to start tonight the yellow key code light stayed on. At least i now know that the starting problems are to do with the immobiliser. My question is what do i need to get done to cure this problem? Is it just a case of having the code in the keys redone? If so how much will this cost? I assume it is going to be a lot cheaper than if it was a problem with the starter motor etc. Is there anyone else who have had this problem.
 
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#7 ·
I think i am all sorted. I spoke to Jamie Porter at Alfaworkshop this moring as he was the one who asked me to keep an eye on the key code light. He told me to look for the code box re: the immobiliser which is above the fuse box. Jamie said to unplug the connecter and reconnect it 2 or 3 times. I fiddled about in the fuse box moving some wires to the side but could not fine this box. He said it was around 3" x 3" x1". I give up looking for it as i had to go to town. Problem was when i went to start the car it would not start and the key code light remained on. I did not worry as it alwys started at the second attempt. However it did not start on the second or third or fourth attempt and the jey code light remained light while trying to start the car s**t!!!
I went to town in my wifes car and when i returned i was determined to find this bloody box. I eventually found a 3" x 3" x 1" black box not directly above the fuse box but to the left/ I had to use a torch and a mirrir to find it. It had a plug at each end. I removed both and plugged them in 3-4 times. Low and behold the car started first time and has done half a dozen times since then.Jamie said "The contacts corrode and it gets a bad signal to the code box" I guess the reason i had to unplug and plug it in several times was to get a better connection on the connectors. It must be the right box as it started straight after removing these plug and one of the connectors wires lead up towards the ignition barrel. I still don't know why after my first search the car would not start even though i failed to find the box. Maybe while i was blindly sticking my had up behind the fascia i moved one of the wires leading to the connector into the black box, and if the connection was not that great this might by the reason.
Might be worth checking the connector that you mentioned and making sure they are properly connected.
 
#8 ·
Hiya,think maybe this could be similar to my problem (156 V6).Yellow code light on with red injector light on intermittantly!,will not start in this condition!.I'll try cleaning connections .Dealer has ordered Code card to try & cure this problem,lets hope i cure it first.Can any one recommend a vat registered garage in Birmingham area,ta.
 
#12 ·
look for a thread by me called' immobilser guide to fixing'
 
#20 ·
Check if there's power going to the box and if the box is connected to the ECU, use a multimeter to measure the voltage and check the continuity between the plug at the immo box and the plug at the ECU, look up the correct pin to test on the eLearn manual's wiring diagram.
 
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