Re: Fault code 2 1 4 2, knock sensor

[Gisli Ottarsson <gisli@master.adams.com>]

So, the answer may lie in a combination of the following:

  1) Hook sensor up to oscilloscope, tap block, see if "knock" was
     sensed.

  2) Check knock sensor wire contact at rear of engine bay.  Ensure
     that green is not connected to red, unless operating on gold
     plated replacements.

  3) "Find a friend" --- with a twist. Remove the sensor, referring to
     it as Frank as I do so.  Then when I put it back in, I'll call it
     Phil --- or is the engine wise to this trick?  Torque to 20Nm,
     *exactly*.

Thanks a lot, fellows.  I'll follow up when successful.

  Gisli


>>>>> On Thu, 15 Jul 1999 08:46:06 GMT, Phil Payne said:

  PP> We call this the "find a friend" code.  We just get two cars and
  PP> swap 'em over.  Torque is _CRITICAL_ to proper knock sensor
  PP> operation - it has to be _exactly_ 20Nm.  I have a TengTools
  PP> torque wrench from 5Nm to 25Nm that I keep from precision stuff
  PP> like metering heads, and I use that and a 15mm Stahlwille
  PP> Crowfoot socket to tighten knock sensors.

  PP> Even then, taking them out and putting them back in can occasionally
  PP> solve problems.  The knock sensor is the closest the MAC1x series of
  PP> ECUs comes to the bleeding edge of technology.

  PP> Also check the contacts in the carrier at the rear of the engine bay.
  PP> Note that a 'green' knock sensor cable shouldn't be plugged in to a
  PP> 'red' socket unless the pins in the socket are replaced with gold
  PP> plated ones.

  PP> --
  PP>  Phil Payne
  PP>  UK Audi quattro Owners Club
  PP>  Phone: 0385 302803   Fax: 0870 0883933


-- 
Gisli Ottarsson, PhD                     
Mechanical Dynamics Inc.            gisli@adams.com    
2301 Commonwealth Blvd.             Tel: 1-734-913-2550
Ann Arbor, Michigan 48105           Fax: 1-734-994-6418