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Check engine light on
  • roadtek
  • Massachusetts, United States
Note: I did enter the wrong model #, It is actually a GC25P5. I have a tier lll Doosan with 3 faults listed: 721, 772, and 921. It starts and runs, ( a little rough, and after reaching operating temp. it runs rich) My motoservice will connect and read the motor, but I have no chart for 3 digit codes. Any help is appreciated. Thanks.
  • Posted 18 Jan 2013 03:46 AM
  • • Modified 18 Jan 2013 04:42 AM by poster
Total replies: 1. Showing items 1 - 1 of 1 results.
  • kevin_t
  • Pennsylvania, United States
Code 712:

In LPG mode, system had to
adapt rich more than expected

Check: Check for vacuum leaks.
Check fuel trim valves, [url removed] leaking
valve or hose
Check for missing orifice(s).

Code 772:

Pre-catalyst O2 sensor indicates
extended rich operation on LPG

Check: Correct other faults that may
contribute to 772 ([url removed] faults
pertaining to FTVs, Pre-Cat O2,
Post Cat O2 sensor)
Look for leaks in exhaust, catalytic
converter, HEGO sensors; repair
Check all sensor connections (see
fault 742 corrective actions).

Code 921:

Pre-catalyst O2 sensor voltage
out of range high, sensor signal
shorted to power

Check: Check if O2 sensor installed before
catalyst is shorted to 5Vdc or
O2 (signal) Pin 3 to SECM Pin B13
SECM (XDRP 5V) Pin B24
SECM (DRVP 12V) Pin A23
  • Posted 18 Jan 2013 07:13 AM
Total replies: 1. Showing items 1 - 1 of 1 results.

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