Measuring block 000 in 3B engine in the '91 200 20V

Steve Eiche seiche at
Wed Apr 16 07:31:35 EDT 2003

Someone asked for measuring block value for the 3B a day or so ago.
FWIW, our ProDiag system has the labels for block 000 on the 3B.  These
are the same for the AAN/ABY/ADU engines as well I believe. Here is the

Chnl Description  Values     Corresponds to:    Use
1    Engine temp. 184-215     85-105C           Temp. sensor on head
2    Engine load  20-25      (boost @RPM?)      Air leaks in system
3    Engine RPM   77-83 (idle)RPM/10            Only read to 2550RPM
4    IAC range    121-135     idle valve range  air leaks or excess load
5    IAC 0 point  80-125      calc'd by ECU     IAC leaks or faulty IAC
6    IAC adaption 123-127     Quant. IAC change Air leaks
7    IAC control  41-55       calc'd by ECU     Air leaks or faulty IAC
8    O2 control   123-133     02 sensor reading O2 sensor and mixture
9    O2 Adapt.    115-141     ECU 02 adapt. val Mixture, MAF, air leaks
10   Timing       35-37 (idle)8-12BTDC          Timing check

See the Bentley manuals for the best use of this data.  FWIW, all of
this data can be very useful in diagnosing 3B behavior, even if you are
not setting DTCs.  For example, a dead temp sensor on the head can
easily be found by looking at the value of Channel 1.  O2 can be
monitored by channel 8.  Vacuum/boost leaks can be discovered with the
IAC (Idle Air Control) channel readings.  Tuners use the O2 sensor and
timing readings for quick verification of their code.


Steve Eiche
Shade Tree Software, LLC

More information about the 200q20v mailing list