PCM2 - Code 800A - Microphone not connected

[GaryFB]

2003, Boxster S, 025,268 miles. Using the PST2 I have a PCM2 Code 800A - Microphone not connected. I have followed the diagnostic proceedure in the Porsche Manual (checking the wires), I have replaced the microphone (996-646-307-04-A03) with a new part purchased from the dealer. The code will not erase even with the new microphone. When I perform automated self test for the microphone and speakers, using the PST2, both pass the test. According to the Porsche Manual, I need to replace the BOSE amplifier control module. Has anyone ever experienced this fault code? Will a new BOSE amplifier control module fix this problem?

The following is the Code Data:

Fault type: Limit exceeded - present

Lock Status of MOST ring: lock

Supply voltage: 13.4 v

Frequency counter: 50

MOST unlock counter: 93

MOST transmission error: 12

Fault Memory could not be erased

Can anyone explain the above Code Data?

Thank you.

[GaryFB]

My diagnostic manual says:

"800A PCM2 - gateway

CAN comfort timeout, air-conditioning system"

Do you have any other symptoms?

Hi Loren; thank you for the quick response. No, there are no symptoms. Why is the fault recorded and why will the fault not erase? I have attached the pages form the manual and the data from the PST2. Thank you.

Codes.pdf

[Loren]

You remember that with the PST2 you always have to read the fault then clear it in that order? If you do other functions then come back to erase faults it won't do it.

I'm trying to remember a thing with PCM1/2 where you have to clear the fault - turn the ignition off (removing the key) - then put the key in and read it again before it will show as erased.

You are right the diagnostics say it is the amp. I have heard of some amp failures but those have usually been total sound failures.

[GaryFB]

You remember that with the PST2 you always have to read the fault then clear it in that order? If you do other functions then come back to erase faults it won't do it.

I'm trying to remember a thing with PCM1/2 where you have to clear the fault - turn the ignition off (removing the key) - then put the key in and read it again before it will show as erased.

You are right the diagnostics say it is the amp. I have heard of some amp failures but those have usually been total sound failures.

Hi Loren; yes, I Read the Fault first, then go to Erase Fault, but it will not allow me to erase. I removed the instrument panel, inspected the microphone, the wires, and performed the resistance tests as per the Porsche Manual. I even replaced the microphone. I performed the Automated Test of the BOSE microphone and speakers, and both pass. But the Fault Code remains. The Fault Data says the fault is Present. The system self tests itself and passes, but it also sees a fault. I call that a contradiction. I wonder if there is a software problem in the BOSE amp module? I guess I have to replace it to find out. I just hate guessing. I hate when the Trouble Chart ends with replace with new module. I will try recycling the key and erasing the code, I think I have done this, but I will do it as a proceedure. Thanks again.

[GaryFB]

TSB 13/04 W522 Dated 04-15-2005 applies to this car. The PCM2 Software Version is 3.0 and the BOSE amp Software version is 000 119 20. The TSB indicates there is an update for the BOSE amp. I do not know if that will fix the Code 800A, but I suspect I should try. Does anyone have experience with this TSB ?

[GaryFB]

You remember that with the PST2 you always have to read the fault then clear it in that order? If you do other functions then come back to erase faults it won't do it.

I'm trying to remember a thing with PCM1/2 where you have to clear the fault - turn the ignition off (removing the key) - then put the key in and read it again before it will show as erased.

You are right the diagnostics say it is the amp. I have heard of some amp failures but those have usually been total sound failures.

Hi Loren; I have received these two CD Rom Updates relating to the TSB. I will let you know what happens.

[GaryFB]

You remember that with the PST2 you always have to read the fault then clear it in that order? If you do other functions then come back to erase faults it won't do it.

I'm trying to remember a thing with PCM1/2 where you have to clear the fault - turn the ignition off (removing the key) - then put the key in and read it again before it will show as erased.

You are right the diagnostics say it is the amp. I have heard of some amp failures but those have usually been total sound failures.

Hi Loren; The Porsche-BOSE CD Rom software Update fixed the PCM2 code. Thanks for your help.

[Loren]

Thanks for the feedback. I'm glad we know what will fix that fault - now.