Woodward GECO, Technical Manual, Page: 80 / 90

GECO

Stoichiometric Manual 03554
72 Woodward
Valve Limit Low and High:
Fluctuating fuel supply pressure
Fuel metering valve
Carburetor not tracking well
Low authority due to low pressure and rich
carburetor settings
Adaptive Limit Low:
Downstream EGO3 health
Fuel metering valve
Set EGO Base lower to re-center adaptive
authority “window”
Adaptive Limit High:
Downstream EGO3 health
Fuel metering valve
Set EGO Base higher to re-center adaptive
authority “window”
DC Power Supply Low:
Power supply
Poor connection
DC Power Supply High:
Power supply
Short to other voltage source
Computer:
ECU
Trigger:
Other high-voltage or high-current wires near
G-lead wiring
Unshielded G-lead wiring
Ignition system problem (magnetic pickup)
EGO Signal High:
EGO - check EGO health
EGO signal ground open
Other wiring problems (short)
ECU
EGO Health Low:
EGO - check EGO health
Signal wiring problem
ECU
TC Open:
Open TC circuit
TC
ECU
TC Lower than Expected:
TC not in exhaust stream
Shorted TC circuit
TC
ECU
Valve Current Low:
Open valve circuit
Valve wired wrong (polarity, 2 valves in series)
Fuel metering valve
ECU
Valve Current High:
Shorted valve circuit
Valve wired wrong (2 valves in parallel)
Fuel metering valve
ECU
TC Temperature Limit:
Ignition problems (misfire, retarded timing)
Engine knock