5B.26
Section 5B
EFI Fuel System
Keep in mind that EFI-related problems are more often
caused by the wiring harness or connections than by
the EFI components. Even small amounts of corrosion
or oxidation on the terminals can interfere with the
milliamp currents used in system operation.
Cleaning the connectors and grounds will solve
problems in many cases. In an emergency situation,
simply disconnecting and reconnecting the connectors
may clean up the contacts enough to restore operation,
at least temporarily.
If a fault code indicates a problem with an electrical
component, disconnect the ECU connector and test for
continuity between the component connector terminals
and the corresponding terminals in the ECU connector
using an ohmmeter. Little or no resistance should be
measured, indicating that the wiring of that particular
circuit is OK. An illustrated listing of numerical terminal
locations, for each style of ECU connector is provided
on pages 5B.26 and 5B.29.
NOTE:
When performing voltage or continuity tests,
avoid putting excessive pressure on or against
the connector pins. Flat pin probes are
recommended for testing to avoid spreading or
bending the terminals.
“24 Pin” (MSE 1.0) Plastic-Cased ECU Systems
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Function
1
Permanent Battery Voltage
Switched Ignition Voltage
Safety Switch
Throttle Position Sensor (TPS) and Temperature Sensor Ground
Not Used
Oil Temperature Sensor Input
Not Used
Throttle Position Sensor (TPS) Input
Speed Sensor Input
Speed Sensor Ground
Oxygen Sensor Input
Not Used (Oxygen Sensor Ground if needed)
Diagnostic Line
Throttle Position Supply Voltage
Battery Ground
Injector 1 Output
Injector 2 Output
Main Relay Output
Malfunction Indicator Light (MIL)
Not Used (Tach Output if needed)
Not Used
Ignition Coil #1 Output
Ignition Coil #2 Output
TPS Initialization Terminal
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
www.mymowerparts.com
