Kohler command pro ECH749 Service Manual page 87

Code 42
Component: Engine (Oil) Temperature Sensor
Fault: Not sending proper signal to ECU.
Condition: Engine may be hard to start because
ECU can't determine correct fuel mixture.
Conclusion: Temperature Sensor Related.
● Sensor wiring or connection.
Engine Wiring Harness Related
"35 Pin" (MA 1.7) Metal-Cased ECU:
● Pin circuits 14 and/or 27A damaged
(wires, connectors) or routed near
noisy signal (coils, alternator, etc.).
● ECU-to-harness connection problem.
Engine Wiring Harness Related
"24 Pin" (MSE 1.0) Plastic-Cased ECU:
● Pin circuits 4, 6 and/or 4A damaged
(wires, connectors) or routed near
noisy signal (coils, alternator, etc.).
● ECU-to-harness connection problem.
Engine Wiring Harness Related
"32 Pin" (MSE 1.1) Plastic-Cased ECU:
● Pin circuits 4, 6 and/or (4A) damaged
(wires, connectors) or routed near
noisy signal (coils, alternator, etc.).
● ECU-to-harness connection problem.
System Related
● Engine is operating above 176°C
(350°F) temperature sensor limit.
24 690 01 Rev. K
Code 43 and 44 "32 Pin" (MSE 1.1) Plastic-Cased
ECU only.
Component: TPS "Auto-Learn" initialization function
Fault:
Condition:
Conclusion: TPS Related
KohlerEngines.com
EFI SYSTEM-BOSCH
failed, throttle angle out of learning range.
While performing TPS "Auto-Learn"
function, measured throttle angle was not
within acceptable limits.
MIL illuminated. Engine will continue to
run but not properly. Upon restart TPS
Auto-Learn function will run again unless
voltage to ECU disconnected to clear
memory.
● TPS rotated on throttle shaft assembly
beyond allowable range.
● TPS bad.
Engine Wiring Harness Related
● Broken or shorted wire in harness.
ECU pin 18 to TPS pin 1.
ECU pin 4 to TPS pin 2.
ECU pin 8 to TPS pin 3.
Throttle Body Related
● Throttle shaft inside TPS worn, broken,
or damaged.
● Throttle plate loose or misaligned.
● Throttle plate bent or damaged
allowing extra airfl ow past, or restricting
movement.
ECU Related
● Circuit providing voltage or ground to
TPS damaged.
● TPS signal input circuit damaged.
87