Service manual

G420F(FE) Service Manual Chapter 9. Advanced Diagnostics 305
Table 2. Diagnostic Fault Codes (Flash Codes) cont’d.
DFC PROBABLE FAULT FAULT ACTION *
CORRECTIVE ACTION
FIRST CHECK
911
O2RangeLow
Pre-catalyst O2 sensor
voltage out of range low,
sensor signal shorted to
ground
(1) TurnOnMil
(2) DisableLiquid O2Ctrl
(3) DisableGas O2Ctrl
Check if O2 sensor installed before the
catalyst is shorted to GND or sensor
GND.
O2 (signal) Pin 3 to SECM Pin B13
SECM (DRVG GND) Pins A16, B17
SECM (XDRG sensor GND) Pin B1
912
O2_PostCatRangeLow
Post-catalyst O2 sensor
voltage out of range low,
sensor signal shorted to
ground
(1) TurnOnMil
(2) Disable Gasoline Post
catalyst O2Ctrl
(3) Disable LPG Post
catalyst O2Ctrl
Check if O2 installed after the catalyst
sensor is shorted to GND or sensor
GND.
O2 (signal) Pin 3 to SECM Pin B19
Possible sources: SECM (DRVG GND)
Pins A16, B17 and SECM (XDRG
sensor GND) Pin B1
921
O2RangeHigh
Pre-catalyst O2 sensor
voltage out of range high,
sensor signal shorted to
power
(1) TurnOnMil
(2) DisableLiquid O2Ctrl
(3) DisableGas O2Ctrl
Check if O2 sensor installed before
catalyst is shorted to +5Vdc or battery.
O2 (signal) Pin 3 to SECM Pin B13
SECM (XDRP + 5V) Pin B24
SECM (DRVP + 12V) Pin A23
922
O2_PostCatRangeHigh
Post-catalyst O2 sensor
voltage out of range low,
sensor signal shorted to
ground
(1) TurnOnMil
(2) Disable Gasoline Post
catalyst O2Ctrl
(3) Disable LPG Post
catalyst O2Ctrl
Check if O2 sensor installed after
catalyst is shorted to +5Vdc or battery.
O2 (signal) Pin 3 to SECM Pin B19
Possible voltage sources: SECM
(XDRP + 5V) Pin B24 and SECM
(DRVP + 12V) Pin A23
931
FuelTempRangeLow
Fuel Temperature
Sensor Input is Low
normally set if the fuel
temperature sensor wire
has shorted to chassis
ground or the sensor has
failed.
TurnOnMil
Check fuel temp sensor connector and
wiring for a short to GND
SECM (signal) Pin B14 to FTS Pin 1
SECM (sensor GND) Pin B1 to FTS
Pin 2
SECM (system GND) Pin A16, B17
932
FuelTempRangeHigh
Fuel Temperature
Sensor Input is High
normally set if the fuel
temperature sensor wire
has been disconnected
or the circuit has opened
to the SECM.
TurnOnMil
Check if fuel temp sensor connector is
disconnected or for an open FTS circuit
SECM (signal) Pin B14 to FTS Pin 1
SECM (sensor GND) Pin B1 to FTS
Pin 2
(*) Fault actions shown are default values specified by the OEM.