4X Vpw Hardware help

So I have a guy working on some hardware for me.

He has run into an issue activation the 4X Vpw, wondering if any had some knowledge to help out.

From His latest Email

Quote:

PLanet

Here is where I am.

Send request to disable normal messaging ---- positive response

Send Request High Speed Mode ------------------- positive response

Send Begin High Speed Mode ------------------------ No response at all

Have not been able to make any more progress. If I send a 4X message to read codes there is no response.

Question - is this the normal sequence to initiate 4X mode?

PLanet

Do you know if the’ Begin High Speed Mode’ has to be sent after the ‘Request High Speed Mode’? I get a positive response to the Request High Speed Mode command but it’s not responding to commands I send at 4X after that.

Thanks

Some more info I have from him

(I have sent him this document) http://planethax.com/PCMcomms.xls

Quote:

Yes. After sending the Begin High Speed Mode, I wait for a response but it never comes. I have tried sending the Begin High Speed Mode in both 1X and 4X speeds but never see a response message, and I have a scope on the bus in case the software misses the response.

Quote:

Here are the transmitted messages:

6CFEF12800000 'send request disable normal messaging

6Cfef1A000 'send request for 4X data

6CfeF1A100 'send request start 4X data, sent at 4x rate

Never see response from the last message

there is no response from the begin high speed mode "A1" message. The idea being that you are telling the PCM to swicth, then both of you switch. If the PCM switches really fast then sends a reply and you haven't yet switched it breaks everything. So once you send the A1 message you both switch, then send another message to see if it worked.

Ah, Thanx.
So the A1 is sent at 1X then switch the Hardware to 4X correct?

yes