XC90 Start Prevented Try Again Problem

[orielg]

I have a 2011 XC90 and last summer it began this intermittent fault of not starting and the message was "Start Prevented, Try Again". We coped with it by keeping the 2 keys in the car as if the first one didn't start it the 2nd key generally would. Now 1 key will not start it 100% of the time and the remaining key will start the car some of the time. Usually if it has been left for a long time.

My excellent independent Volvo mechanic / technician has checked all the error codes and done the following:
1. replaced antenna ring - made no difference
2. checked all the connections
3. Updated CEM software
4. Reprogrammed both Keys (none working key says "wrong key")
5. Have ordered one new key with new transponder which may do it but I am not overly hopeful.

Does anyone have any other ideas. Last resort would be to replace the CEM but that will be expensive. Any help very much appreciated.

[SwissXC90]

Originally Posted by orielg

I have a 2011 XC90 and last summer it began this intermittent fault of not starting and the message was "Start Prevented, Try Again". We coped with it by keeping the 2 keys in the car as if the first one didn't start it the 2nd key generally would. Now 1 key will not start it 100% of the time and the remaining key will start the car some of the time. Usually if it has been left for a long time.

My excellent independent Volvo mechanic / technician has checked all the error codes and done the following:
1. replaced antenna ring - made no difference
2. checked all the connections
3. Updated CEM software
4. Reprogrammed both Keys (none working key says "wrong key")
5. Have ordered one new key with new transponder which may do it but I am not overly hopeful.

Does anyone have any other ideas. Last resort would be to replace the CEM but that will be expensive. Any help very much appreciated.

Does sound like the immobiliser is stopping the engine from starting, OR it could be simply a failled transponder chip in the one key.

I would suggest the following:
1. Ensure that only one car key is on the key ring when the Volvo key is in the ignition. If you have another car key, there is a chance the radio signal is being interferred with. Small chance, but likely.

2. Check the wiring from the igniiton switch ring antenna all the way back to the CEM. It is a direct cable connection from the antenna ring to the CEM
Check in particular:
Pin 7, brown wire. This is ground.
Pin 1, blue-red wire. This is power direct from the ignition switch, and must be live in posiiton II and III. If in doubt, try bypassing the power feed directly from the fusebox
Pin 2, green wire. Antenna Signal to the CEM, to CEM connector D pin 57
Pin 3, blue wire. Antenna Signal to the CEM , to CEM connector D pin 58

Check the connections of all ring antenna connector pins. They must be clean and dry and free from corosion.

Check the CEM connector D pins 57 and 58, look very carefully for signs of any water damage on the CEM (leaky sunroof drains)
Any water staining is a danger sign! The CEM will likely have corrosion damage if you see any water staining around the CEM.
Check also your floor carpet: is it perfectly dry, or damp.
If damp, suspect a water leak problem from the sunroof drain.

Certainly a new key is the cheapest next step, replacing the CEM costs a lot more - BUT may be required if it has water damage

[orielg]

Thanks very much - will give this to our mechanic on Monday and keep Thread updated

[Moonhammer]

Hi,

Did you managed to get this resolved ? I have the same Volvo and have started getting the same “start prevented, try again” problem.

[Familyman 90]

This happened to me after I dropped my keys. The key would then rarely, if ever, start the car.

In my case the spare key worked 100% so I ordered a new key and that cured the problem completely. The key wasn't cheap, but when I payed £49,000 new for the car in November 2008 I kinda guessed stuff like this might cost a good few shekels so I can't complain.

Let us know how you get on.