Specifications

Operation Section
-123-
Table 2. Diagnostic Fault Codes (Flash Codes) cont’d.
DFC PROBABLE FAULT FAULT ACTION * CORRECTIVE ACTION FIRST CHECK
852
LiqPostO2FailedLean
Pre-catalyst O2 sensor
indicates extended lean
operation on gasoline
(1) TurnOnMil
(2) DisableLiqPost
O2Ctrl
(Certified Units Only)
Correct other faults that may contribute to 852
(e.g. faults pertaining to Injectors, MAP, IAT,
Pre-Cat O2, Post Cat O2 sensor)
Look for leaks in exhaust, catalytic converter,
HEGO sensors; repair leaks.
Check all sensor connections (see fault 842
corrective actions).
871
LiqO2FailedRich
Pre-catalyst O2 sensor
indicates extended rich
operation on gasoline
(1) TurnOnMil
(2) DisableLiquid
O2Ctrl
(3)DisableLiquid
PostO2Ctrl
High gasoline fuel pressure, perform gasoline
pressure test
Injector problems, e.g. leaking, defective injector
872
LiqPostO2FailedRich
Pre-catalyst O2 sensor
indicates extended rich
operation on gasoline
(1) TurnOnMil
(2) DisableLiq
PostO2Ctrl
(Certified Units Only)
Correct other faults that may contribute to 872
(e.g. faults pertaining to Injectors, MAP, IAT,
Pre-Cat O2, Post Cat O2 sensor)
Look for leaks in exhaust, catalytic converter,
HEGO sensors; repair leaks.
Check all sensor connections (see fault 842
corrective actions).
911
O2RangeLow
Pre-catalyst O2 sensor
voltage out of range low,
sensor signal shorted to
ground
None N/A
912
O2_PostCatRangeLow
Post-catalyst O2 sensor
voltage out of range low,
sensor signal shorted to
ground
None N/A
921
O2RangeHigh
Pre-catalyst O2 sensor
voltage out of range high,
sensor signal shorted to
power
(1) TurnOnMil
(2) DisableLiquid O2Ctrl
(3) DisableGas
O2Ctrl
(Certified Units Only)
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 asoline
Post-catalyst
O2Ctrl
(3) Disable LPG
Post-catalyst
O2Ctrl
(Certified Units Only)
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
(Certified Units Only)
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
(Certified Units Only)
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.