Kohler Command PRO ECV630 Service Manual page 75

● Ignition switch
● Permanent ECU power circuit problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Pin circuit 1.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Pin circuit 1.
● Switched ECU power circuit problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Pin circuit 2.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Pin circuit 2.
● ECU grounds
● ECU
Diagnostic Aid #2 "FAULT CODES" (Refer to detailed
fault code listing before flow chart and servicing
information for respective components)
● Code 21-Engine Speed Synchronization
● Code 22-Throttle Position Sensor (TPS)
● Code 23-Engine Control Unit (ECU)
● Code 31-Oxygen Sensor
● Code 32-Oxygen Sensor
● Code 33-Fuel System (temporary adaptation factor)
● Code 34-Fuel System (permanent adaptation factor)
● Code 42-Engine (Oil) Temperature Sensor
● Code 43-TPS "Auto-Learn" Initialization Function
(Below Min. Limit), "32 Pin" (MSE 1.1) Plastic-Cased
ECU only.
● Code 44-TPS "Auto-Learn" Initialization Function
(Above Max. Limit), "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 51-Injector 1, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 52-Injector 2, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 55-MIL Light, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 56-Pump Relay, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 61-End of Fault/Blink Code Transmission.
Diagnostic Aid #3 RUN/ON (MIL remains "on" while
engine is running)*
Possible causes:
● Fault codes which turn on MIL when engine is running.
● Code 21-Engine Speed Synchronization
● Code 22-Throttle Position Sensor (TPS)
● Code 23-Engine Control Unit (ECU)
● Code 31-Oxygen Sensor (shorted)
● Code 34-Fuel System (permanent adaptation at limit)
● Code 42-Engine (Oil) Temperature Sensor
● Code 43-TPS "Auto-Learn" Initialization Function
(Below Min. Limit), "32 Pin" (MSE 1.1) Plastic-Cased
ECU only.
● Code 44-TPS "Auto-Learn" Initialization
● Function (Above Max. Limit) "32 Pin" (MSE 1.1)
Plastic-Cased ECU only.
● Code 51-Injector 1, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 52-Injector 2, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 55-MIL Light, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● Code 56-Pump Relay, "32 Pin" (MSE 1.1) Plastic-
Cased ECU only.
● MIL circuit grounded between light and ECU.
"35 Pin" (MA 1.7) Metal-Cased ECU: Pin circuit 31.
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Pin circuit
19.
24 690 02 Rev. D
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Pin circuit
29.
● ECU
Diagnostic Aid #4 SPEED SENSOR (MIL does not turn
off during cranking). Indicates ECU is not receiving a
signal from speed sensor.
Possible causes:
● Speed sensor
● Speed sensor circuit problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Pin circuits
9 and 10.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Pin circuits
9 and 10.
● Speed sensor/toothed wheel air gap
● Toothed wheel
● Flywheel key sheared
● ECU
Diagnostic Aid #5 FUEL PUMP (fuel pump not turning
on)
Possible causes:
● Fuel pump fuse
● Fuel pump circuit problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Circuits 30,
87, and relay.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Circuits 30,
87, and relay.
● Fuel pump
Diagnostic Aid #6 "RELAY" (relay not operating)
Possible causes:
● Safety switches/circuit(s) problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Circuit 3.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Circuit 25.
● Relay circuit(s) problem
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Circuits 18,
85, 30, and 87.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Circuits
28,85, 30, and 87.
● Relay
● ECU grounds
● ECU
Diagnostic Aid #7 "IGNITION SYSTEM" (no spark)
Possible causes:
● Spark plug
● Plug wire
● Coil
● Coil circuit(s)
"24 Pin" (MSE 1.0) Plastic-Cased ECU: Circuits 22,
23, 65, 66, 30, and relay.
"32 Pin" (MSE 1.1) Plastic-Cased ECU: Circuits 30,
31, 65, 66, relay and relay circuit 30.
● ECU grounds
● ECU
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