Generac Power Systems GP Series Diagnostic Repair Manual page 39

MIL Fault Circuit at Fault
Code Action
Ignition
4-1 Shutdown Ignition Coil -
Cylinder 1
4-2 Shutdown Ignition Coil -
Cylinder 1
4-3 Shutdown Ignition Coil -
Cylinder 2
4-4 Shutdown Ignition Coil -
Cylinder 2
Speed and Position
5-1 Shutdown Engine Speed
5-2 Shutdown Engine Speed
5-3 Shutdown Throttle Valve
Feedback
5-4 Shutdown Throttle Valve
Feedback
5-5 Shutdown Throttle Valve
5-6 Shutdown Throttle Valve
5-7 Shutdown Crankshaft
Position
5-8 Shutdown Starter
Diagnostic Repair Manual
Fault Type
Current measured though ECM-4M is below
normal range, coil resistance high
Current measured though ECM-4M is above
normal range, coil resistance low
Current measured though ECM-1M is below
normal range, coil resistance high
Current measured though ECM-1M is above
normal range, coil resistance low
Engine speed above normal operating range
Engine speed below normal operating range
Position sensor voltage (ECM-3B) above
normal range
Position sensor voltage (ECM-3B) below
normal range
Throttle valve stepper motor circuit fault
Throttle valve mechanically stuck or not
properly responding
No signal detected from engine speed sensor
Starter motor not cranking engine
Section 5 Engine Diagnostic Tests
Go To...
Disconnect coil and test resistance
Faulty coil
Disconnect coil and test resistance
Check wiring for OPEN
Disconnect coil and test resistance
Faulty coil
Disconnect coil and test resistance
Check wiring for OPEN
Throttle plate stuck open
Faulty TTMAP sensor
Stepper motor not operating correctly
Stepper motor not operating correctly
Throttle plate malfunction
Faulty TTMAP sensor
Stepper motor not operating correctly
Throttle plate malfunction
Faulty TTMAP sensor
Check wiring for shorts
Stepper motor not operating correctly
Throttle plate malfunction
Faulty TTMAP sensor
Check wiring for opens
Stepper motor not operating correctly
Check wiring for opens or shorts
Check function throttle plate
Check wiring
Check for secure installation of CKP
Faulty sensor
Check wiring and harness
Check starter relay
Test battery, cables and starter
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