Doosan D20S-5 Operation & Maintenance Manual page 115

( ) Fault actions shown are default values specified by the OEM. ( ) Fault actions shown are default values specified by the OEM.
Table 2. Diagnostic Fault Codes (Flash Codes) cont'd. Table 2. Diagnostic Fault Codes (Flash Codes) cont'd.
DFC DFC PROBABLE FAULT PROBABLE
GasFuelAdaptRangeHi GasFuelAdaptRangeHi
In LPG mode, system had In LPG mode, system had
731 731
(73) (73) to adapt lean more than to adapt lean more than
expected expected
GasDesEquivHi GasDesEquivHi
In LPG mode, system had In LPG mode, system had
732 732
to adapt rich more than to adapt rich more than
expected expected
GasO2NotActive GasO2NotActive
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
741 741 inactive on LPG, open O2 inactive on LPG, open O2
(74) (74) sensor signal or heater sensor signal or heater
leads, defective O2 leads, defective O2
sensor sensor
GasPostO2NotActive GasPostO2NotActive
Post-catalyst O2 sensor Post-catalyst O2 sensor
inactive on LPG, open O2 inactive on LPG, open O2
742 742
sensor signal or heater sensor signal or heater
leads, defective O2 leads, defective O2
sensor. sensor.
743 743 GasCatInactive GasCatInactive
GasO2FailedLean GasO2FailedLean
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
751 751
indicates extended lean indicates extended lean
operation on LPG operation on LPG
GasPostO2FailedLean GasPostO2FailedLean
Pre-catalyst O2 sensor Pre-catalyst O2 sensor
752 752
indicates extended lean indicates extended lean
operation on LPG operation on LPG
GasO2FailedRich GasO2FailedRich
771 771 Pre-catalyst O2 sensor Pre-catalyst O2 sensor
(77) (77) indicates extended rich indicates extended rich
operation on LPG operation on LPG
FAULT FAULT FAULT ACTION ACTION * *
(1) TurnOnMil (1) TurnOnMil
(2) Disable (2) Disable
GasO2 Ctrl GasO2 Ctrl
(3) Disable (3) Disable
GasPost O2Ctrl GasPost O2Ctrl
None None
(1) TurnOnMil (1) TurnOnMil
(2) DisableGas (2) DisableGas
O2Ctrl O2Ctrl
(3) Disable (3) Disable
GasPost O2Ctrl GasPost O2Ctrl
(1) TurnOnMil (1) TurnOnMil
(2) (2) DisableG DisableGasPost asPost
O2Ctrl O2Ctrl
None None
(1) TurnOnMil (1) TurnOnMil
(2) DisableGas (2) DisableGas
O2Ctrl O2Ctrl
(3) Disable (3) Disable
GasPost O2Ctrl GasPost O2Ctrl
(1) TurnOnMil (1) TurnOnMil
(2) DisableG (2) DisableGasPost asPost
O2Ctrl O2Ctrl
(1) TurnOnMil (1) TurnOnMil
(2) DisableGas (2) DisableGas
O2Ctrl O2Ctrl
(3) DisableG (3) DisableGasPost asPost
O2Ctrl O2Ctrl
-112- -112-
CORRECTIVE ACTION CORRECTIVE
Check dual dither valves, e.g. plugged valve or Check dual dither valves, e.g. plugged valve or
hose. hose.
Check for plugged orifice(s). Check for plugged ori
Check that Pre-catalyst O2 sensor connectio Check that Pre-catalyst O2
are OK. are OK.
O2 (signal) Pin 3 to SECM Pin B13 O2 (signal) Pin 3 to SECM Pin B13
O2 Pin 2 O2 Pin 2 (HEATER GND) to SECM (DRVG (HEATER GND) to SECM (DRVG
GNG) Pins A16, B17 GNG) Pins A16, B17
O2 Pin 1 (HEATER PWR) to SECM (DRVP + O2 Pin 1 (HEATER PWR) to SECM (DRVP +
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 (HEATER GND) to Pin 1 (HEATER
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 (HEATER GND) to SECM (DRVG
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
and SECM has calculated that water and SECM has calculated that water
condensation in exhaust has been removed by condensation in exhaust has been re
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 (HEATER GND) to Pin 1 (HEATER
PWR) PWR)
Check for vacuum leaks. Check for vacuum leaks.
Check dual dither valves, e.g. leaking valve or Check dual dither valves, e.g. leaking valve or
hose. hose.
Check for missing orifice(s). Check for mi ssing orifice(s).
Correct other faults that may contribute to 752 Correct other faults that may contribute to 752
(e.g. faults pertaining to dither valves, Pre-Cat (e.g. faults pertaining to dither valves, Pre-Cat
O2, Post Cat O2 sensor) O2, Post Cat O2 sensor)
Check for vacuum leaks Check for vacuum leaks
Check for leaks in exhaust, catalytic converter, Check for leaks in exhaust, catalytic converter,
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).
Check dual dither valves, e.g. plugged valve or Check dual dither valves, e.g. plugged valve or
hose. hose.
Check for plugged orifice(s). Check for plugged ori
Operation Section Operation Section
ACTION FIRST FIRST CHECK CHECK
fice(s).
N/A N/A
sensor connections
± 0.4 ± 0.4 ) )
Ω Ω Ω Ω
moved by
ter.
± 0.4 ± 0.4 ) )
Ω Ω Ω Ω
N/A N/A
fice(s).
ns