Mine doesn't have OBDII. According to this link:
Ignition timing for the 4500cc petrol motor

Jumping those pins puts the engine (ECU?) in service mode. Do you know what 'service mode' means? When I tested the timing initially it was ranging from 17 degrees advanced to way off the scale as the rpm's move from the initial high rpm's when it was started and once it settled down.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13