Kohler ECV940 Service Manual page 36

EFI SYSTEM-ELECTRONIC THROTTLE BODY (ETB)
ETB EFI Wiring Harness High Output Charging System Detail
A Rectifi er-Regulator
E Red
I Pink
M White
Q Dark Blue
U Yellow/Black
Y Purple
AC Light Green
AG Ignition Coil #2
AK TMAP Sensor
*Main engine harness has 30A fuse, but this fuse is nonfunctional in High Output Charging System, as 30A charging
circuit has been disabled. Refer to equipment manual for fuse detail in OEM supplied wiring harness.
Crankshaft Position Sensor
A sealed, non-serviceable assembly. If fault code P0337 is present and engine does not start/run, proceed to step 1. If
P0337 is present and engine operates, clear codes and retest. If Fault Code diagnosis indicates a problem within this
area, test and correct as follows.
1. Inspect wiring and connections for damage or problems.
2. Make sure engine has resistor type spark plugs.
3. Disconnect Black connector from ECU.
4. Connect an ohmmeter between #4 and #13 pin terminals. A resistance value of 325-395 Ω at room temperature
(20°C, 68°F) should be obtained.
5. If resistance is correct, remove blower housing.
6. Disconnect crankshaft position sensor connector from wiring harness. Test resistance between terminals. A
reading of 325-395 Ω should again be obtained.
a. If resistance is incorrect, remove screws securing sensor to mounting bracket and replace sensor.
b. If resistance in step 4 was incorrect, but resistance of sensor alone was correct, test wire harness circuits
between sensor connector terminals and corresponding pin terminals (#4 and #13) in main connector. Correct
any observed problem, reconnect sensor, and perform step 4 again.
7. If resistance in step 4 is correct, check mounting, fl ywheel teeth (damage, run-out, etc.), and fl ywheel key.
8. When fault is corrected and engine starts, clear fault codes following ECU Reset procedure.
Throttle Position Sensor (TPS)
TPS is a sealed, non-serviceable internal part of electronic throttle body assembly. If diagnosis indicates a bad sensor,
complete electronic throttle body replacement is necessary. If a blink code indicates a problem with TPS, it can be
tested as follows:
Diagnostics of sensor: ECU will still have electrical faults captured in fault codes: P0122 & P0123. These electrical
faults still have same meaning as with prior sensor, P0122 detecting low voltage, open circuit, and P0123 for high
voltage conditions between ECU, wire harness, and sensor. Tip: when working with any electrical connection,
remember to keep connections clean & dry. This is best accomplished by cleaning connection thoroughly prior to
disassembly. Contaminated sensor connections can cause premature engine faults. Functionally testing sensor can
no longer be done with simple resistance checks. If either of these two faults is present or a TPS fault is suspected,
recommended diagnostic test is as follows:
If KOHLER Diagnostic System (KDS) Gen 2 is available (see Tools and Aids)
®
Observe throttle percent and raw TPS values through KDS tool. With KDS tool communicating to ECU and key ON
engine not running, these values can be observed using Throttle Position test within KDS tool test options. Select
Throttle Position Test, select desired percent of throttle opening. (For example, 50% requested opening will yield 50%
TPS opening +/- 5%.) It is recommended to perform multiple tests in diff erent throttle opening positions. (For example,
10%, 50%, and 100%.) If any of these tests are found to be outside of specifi ed range, it is recommended to power
engine down, wait 15 seconds, turn engine key switch power to ON position, and using KDS tool, repeat Throttle
Opening Test. If values again are found to be outside of specifi ed range, it is recommended to replace electronic
36
OEM Supplied B+
Wiring Harness
B
with Charging
Fuse*
F Battery
J Fuel Pump Module
N 8-Terminal Connector
R Starter Motor
V 10A Fuse
Z Yellow
AD Fuel Injector #1
Crankshaft Position
AH
Sensor
Engine Temperature
AL
Sensor
KohlerEngines.com
OEM Supplied Ground
C
Wiring Harness
G Black
K Tan
O Red/Yellow
S Dark Green
W Grey Connector
AA Black/White
AE Fuel Injector #2
AI Oxygen Sensor
Diagnostic Connector
AM
(8 Bay, 7 Pin)
D Stator
H Red/Black
L Red/White
P Green/White
T Oil Pressure Switch
X Black Connector
AB Grey
AF Ignition Coil #1
Electronic Throttle
AJ
Control
62 690 05 Rev. H