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Discussion Starter · #1 ·
Hi, I just wanted to relate an issue I've had with this OBD-II port
reader/datalogger.
It is similar to the MSD Dashhawk, but unlike that unit, it is not
discontinued, the support is there, and courteous and prompt
to reply to questions. It also datalogs more PIDs at once than
the Dashhawk can.

My issue with this DashDyno logger/reader is, that is doesn't seem to
be able to get a 'Knock Retard' value from my Mazdaspeed3.


My question to anyone owning one of these, either a MS3 or Mazda3
is, do you ever show a value for Knock Retard?

Is my knock sensor busted or what?!?
Is my car so amazingly better built than 99.999% of the Mazdaspeed3
owners out there that report some values for knock at most all times?

Attached is a relevant datalog capture picture, detailing some PIDs
but more importantly, the 2 Knock Retard PIDs, which always
display and empty value, or a zero value.


Snappy
 

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Welcome to the forums, Snappy. It's entirely possible that your sensors and ODBII scanner are correct and you're not getting any knock retard under the conditions where this log was taken. The scale on most of those graph lines is really weird, it's impossible to tell at that size what your AFR and air temps are. Also the fuel trims look odd/impossible... is your STFT reporting "100" down the whole graph? That just doesn't make any sense, pretty sure the max trims are +/- 20% or so before you get a CEL (or do you have one?) Also, what octane of fuel are you running?

Try running a log with only 3-4 important PIDs at once (i.e. TPS, RPM, AFR, KR), and get a more accurate scale going for them.
 

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Discussion Starter · #3 ·
UPDATE:

My Knock Sensor may be faulty?


The DashDyno did detect 'knock' when I physically
took a screwdriver and rapped the motor block, near the
sensor. The PID " Knock Retard 2 " then gave a value
for me.

My Dashdyno is working great.



Snappy
 

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Just an FYI, when I use my friend's DDII, it always has trouble with my car. Especially things like 0-60mph times and doing certain data logs. Have you tried the new support update that they offer for it? I believe it corrects some errors on certain Ford/Mazdas. Hope that helps.
 
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