Doosan D20S-5 Operation & Maintenance Manual page 116

(*) Fault actions shown are default values specified by the OEM. (*) Fault actions shown are default values specified by the OEM.
Operation Section Operation Section
Table 2. Diagnostic Fault Codes (Flash Codes) cont'd. Table 2. Diagnostic Fault Codes (Flash Codes) cont'd.
DFC DFC
GasPostO2FailedRich GasPostO2FailedRich
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
772 772
indicates extended rich indicates extended rich
operation on LPG operation on LPG
LiqFuelAdaptRangeHi LiqFuelAdaptRangeHi
In Gasoline mode, system In Gasoline mode, system
821 821
had to adapt lean more had to adapt lean more
than expected than expected
822 822 LiqDesEquivHi LiqDesEquivHi
LiqFuelAdaptRangeLow LiqFuelAdaptRangeLow
In Gasoline mode, system In Gasoline mode, system
831 831
had to adapt rich more than had to adapt rich more than
expected expected
832 832 LiqDesEquivLo LiqDesEquivLo
LiqO2NotActive LiqO2NotActive
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
841 841 inactive on gasoline, open inactive on gasoline, open
O2 sensor signal or heater O2 sensor signal or heater
leads, defective O2 sensor leads, defective O2 sensor
LiqPostO2NotActive LiqPostO2NotActive
Post-catalyst O2 sensor Post-catalyst O2 sensor
842 842 inactive on gasoline, open inactive on gasoline, open
O2 sensor signal or heater O2 sensor signal or heater
leads, defective O2 sensor. leads, defective O2 sensor.
843 843 LiqCatInactive LiqCatInactive
LiqO2FailedLean LiqO2FailedLean
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
851 851
indicates extended lean indicates extended lean
operation on gasoline operation on gasoline
PROBABLE FAULT PROBABLE FAULT
-113- -113-
FAULT FAULT ACTION ACTION * *
Correct other faults that may contribute to 772 Correct other faults that may contribute to 772
(e.g. faults pertaining to FTVs, Pre-Cat O2, (e.g. faults pertaining to FTVs, Pre-Cat O2,
(1) TurnOnMil (1) TurnOnMil
Post Cat O2 sensor) Post Cat O2 sensor)
(2) DisableGasPost (2) DisableGasPost Look for leaks in exhaust, catalytic converter, Look for leaks in exhaust, catalytic converter,
O2Ctrl O2Ctrl HEGO sensors; repair leaks. HEGO sensors; repair leaks.
Check all sensor connections (see fault 742 Check all sensor connections (see fault 742
corrective actions).
corrective actions).
(1) TurnOnMil (1) TurnOnMil Check for vacuum leaks. Check for vacuum leaks.
(2) Disable (2) Disable Low gasoline fuel pressure, perform gasoline Low gasoline fuel pressure, perform gasoline
LiquidO2 Ctrl LiquidO2 Ctrl pressure test. pressure test.
(3) Disable LiqPost (3) Disable LiqPost Injector problems, e.g. plugged, defective Injector problems, e.g. plugged, defective
O2Ctrl O2Ctrl injector. injector.
None None
(1) TurnOnMil (1) TurnOnMil Low gasoline fuel pressure, perform gasoline Low gasoline fuel pressure, perform gasoline
(2) Disable (2) Disable pressure test pressure test
LiquidO2 Ctrl LiquidO2 Ctrl Injector problems, e.g. leaking, defective Injector problems, e.g. leaking, defective
(3) Disable LiqPost (3) Disable LiqPost injector. injector.
O2Ctrl O2Ctrl
None None
Check that Pre-catalyst O2 sensor connections Check that Pre-catalyst O2 sensor connections
are OK. are OK.
O2 (signal) Pin 3 to SECM Pin B13 O2 (signal) Pin 3 to SECM Pin B13
O2 Pin 2 (HEATER GND) to SECM (DRVG O2 Pin 2
(1) TurnOnMil (1) TurnOnMil GNG) Pins A16, B17 GNG) Pins A16, B17
(2) DisableLiquid (2) DisableLiquid O2 Pin 1 (HEATER PWR) to SECM (DRVP + O2 Pin 1
O2Ctrl O2Ctrl
12V) PIN A23 12V) PIN A23
Verify O2 sensor heater circuit is operating by Verify O2 sensor heater circuit is operating by
measuring heater resistance (2.1 measuring heater resistance (2.1
O2 Pin 2 (HEATER GND) to Pin 1 (HEATER O2 Pin 2
PWR) PWR)
Check that Post-catalyst O2 sensor Check that Post-catalyst O2 sensor
connections are OK. connections are OK.
O2 (signal) Pin 3 to SECM Pin B19 O2 (signal) Pin 3 to SECM Pin B19
O2 Pin 2 (HEATER GND) to SECM (DRVG O2 Pin 2
GNG) Pins A16, B17 GNG) Pins A16, B17
O2 Pin 1 (HEATER PWR) to Post O2 Heater O2 Pin 1 (HEATER PWR) to Post O2 Heater
Relay. Relay pin 87. This relay only turns on Relay. Relay pin 87. This relay only turns on
after engine has been running for some time after engine has been running for some time
(1) TurnOnMil (1) TurnOnMil and SECM has calculated that water and SECM has calculated that water
(2) DisableLiqPost (2) DisableLiqPost condensation in exhaust has been re condensation in exhaust has been removed by
O2Ctrl O2Ctrl exhaust heat. Post O2 Heater Relay has exhaust heat. Post O2 Heater Relay has
SECM (DRVP + 12V) applied to the relay coil SECM (DRVP + 12V) applied to the relay coil
power. The relay coil ground is controlled by power. The relay coil ground is controlled by
SECM Pin A20 to activate the relay to flow SECM Pin A20 to activate the relay to flow
current through the post O2 hea current through the post O2 heater.
Verify O2 sensor heater circuit is operating by Verify O2 sensor heater circuit is operating by
measuring heater resistance (2.1 measuring heater resistance (2.1
O2 Pin 2 O2 Pin 2 (HEATER GND) to Pin 1 (HEATER
PWR) PWR)
None None
Check for vacuum leaks. Check for vacuum leaks.
(1) TurnOnMil (1) TurnOnMil Low gasoline fuel pressure, perform gasoline Low gasoline fuel pressure, perform gasoline
(2) DisableLiquid (2) DisableLiquid pressure test. pressure test.
O2Ctrl O2Ctrl Injector problems, e.g. plugged, defective Injector problems, e.g. plugged, defective
injector injector
CORRECTIVE ACTION CORRECTIVE ACTION FIRST FIRST CHECK
N/A N/A
N/A N/A
(HEATER GND) to SECM (DRVG
(HEATER PWR) to SECM (DRVP +
(HEATER GND) to Pin 1 (HEATER
(HEATER GND) to SECM (DRVG
(HEATER GND) to Pin 1 (HEATER
N/A N/A
CHECK
± 0.4 ± 0.4 ) )
Ω Ω Ω Ω
moved by
ter.
± 0.4 ± 0.4 ) )
Ω Ω Ω Ω