Porsche Cayenne Passive Keyless Entry(Kessy) not work

Several days ago,I receive a email sent from one of my blog reader Jack,it about Porsche Cayenne Passive Keyless Entry.Jack said owner of porsche cayenne described that the lock and unlock function of remote key work correctly,but passive keyless entry can not work. Here I rewrite his email content to share the guide on how to solve Porsche Cayenne Keyless Entry trouble.

Trouble Describe:

I found that it is couldn’t open the driver’s side door and other doors when carrying the remote key.Then I park the car on the workshop fault diagnosis station to ensure that the external interference signal is isolated effictively,test the function again and found the syptoms is still exist.

 

Trouble Diagnose:

I used the Porsche Diagnotic Tool to test the key less entry system control unit(Kessy),and find the diagnositic trouble code:0183-inner antenna fault, currently exist. As a result of the previous number of vehicles wiht this same trouble,it seems that all of them have trunk internal antenna trouble.So I replaced the trunk antenna,then test found that keyless entry sysytem function work correctly.But there is doubt that the keyless entry system work after replace the old antenna back.After clearing the trouble code,I drive the car to test the trouble,it disappear.Then I ask owner observing it .

Several days later, the trouble occurs again. I use Piwis to enter the input signal to measure, and read out the door handle sensor data, when my hand close to the door, it display  “Not Start”, it should display  “Starting”. Then I test key password, Kessy power supply and driver’s door power sensor, they all can work. In order to confirm Kessy power voltage, I remove it and test the voltage on the premise of additional simulated load, the result is the voltage has no problem. Then the fault should exists in the inner antenna and Kessy.

Porsche PIWIS 2 V18.15 V17.500 Free Download

 

Then I test the antenna Resistance value in the front and the back of central control platform, also the trunk antenna resistance value, they are all 7Ω , it has no problem. For caution’s sake, I change all inner antennas and test this Resistance value, the trouble still exists. So far, I confirm, the trouble exists in the Kessy.

 

Trouble Troubleshoot:

I replaced Kessy,and after lock the car for 5 min ,I try to start the car find the keyless entry function was still not working, the remote controller unlock button and lock button function is opposite, the starter can’t work. Then I use PIWIS II enter setting / control unit learning function, and match the car key to Kessy,after match successfully, keyless entry function and remote controller button can work. I try to start the engine, it immediately turn off. I try again, no react, then I use Piwis Tester II to read out engine control unit(DME), the trouble code is 0513 immobilizer system key is not correct, currently exist. According to boot failure inquiry, I know the anti-theft lock program in the DME is not correct. Then I use trouble code scanner enter into DME to do immobilizer system program, then start the engine, it can  start successfully. Later this trouble code does not occur any more, the trouble is solved.

Conclusion:

when I diagnose the fault for the first time, it is not easy to find out where the fault is because the fault disappears soon. As for this occasional fault, it needs enough time to observe. If the fault does not influence driving safety, the driver can observe when driving, requesting the driver record some information about the fault, including: time, frequency, symptom, place, climate and more, these information will be very helpful for  our technician.
When I diagnose the fault for the second time, the fault keep exist, so I can one-by-one check parts that may have fault from the small part to the bigger part, from the simple one to the sophisticated one, until I find out the part which has fault.

Fault Conclusion: if the car leakage, you are expected to step-by-step check the reasons starting from the bus tread, you are not suggested to aimlessly disconnect all fuses or control unit, and you’d better use Current Clamp to test.