Daewoo G420E Service Manual page 59

Table a. MI-04 Diagnostic Fault Codes (Flash Codes)
DFC Probable Fault
72 AFRTrimValveLowerDC
FTV duty cycle at lower (lean) limit
73 AFRTrimValveUpperDC
FTV duty cycle at high (rich) limit
(Expected fault when FTV connector
is unplugged)
Tier
G420E/G424E LP Engine
Action
Stored Fault Code
(MIL, Disable Adaptive
learns)
Stored Fault Code
(MIL, Disable Adaptive
learns)
58
Corrective Action, First Check
Engine measured Air/Fuel ratio at the
O2 sensor is excessively lean
Check for intake manifold leaks
Check balance line (vacuum
hose) connection at the regulator
Check N-CA55-500-TR mixer for
heavy end build-up and
operation (see mixer section)
Check N2001 secondary for
operation or low primary
pressure (see N2001 Regulator
section)
Note: If LP-Gas fuel in LP tank is not
enough, this fault code can be set. If
LP tank is frozen, this fault code can
be set, too. It is not system trouble.
Engine measured Air/Fuel ratio at the
O2 sensor is excessively rich
Check FTV connector wiring for an
open circuit
FTV PIN A (SIGNAL) TO PIN B
(PWR)
Check FTV for an open coil by
disconnecting the FTV connector and
measuring the resistance (~26Ω +/-
2Ω)
FTV PIN A (SIGNAL) TO PIN B
(PWR)
Check N-CA55-500-TR mixer for
heavy end build-up and
operation (see mixer section)
Check N2001 secondary for
operation (see N2001 Regulator
section)
Advanced Diagnostics