Troubleshooting Flow Chart - Kohler LH630-775 Service Manual

Code: 55
Source: MIL (Diagnostic lamp) circuit open,
shorted to ground, or shorted to
battery.
Explanation: MIL is not functioning because the
circuit is open, shorted to ground, or
shorted to battery.
Expected Engine
Response: Engine will run normally if no other
errors are present.
Possible Causes:
1. MIL (diagnostic lamp) related
a. MIL element opened or element shorted to
ground.
b. Lamp missing.
2. Engine wiring harness related
a. Broken or shorted wire in harness. ECU pin
29 to lamp open or shorted.
3. Vehicle wiring harness related
a. Broken or shorted wire in harness. Power
lead to MIL open or shorted.
4. ECU related
a. Circuit controlling lamp damaged.
Code: 56
Source:
Fuel pump relay circuit open, shorted
to ground, or shorted to battery
Explanation: Fuel pump, ignition coils, and fuel
injectors will not function because
the fuel pump relay circuit is either
open, shorted to ground, or may be
"on" continuously if shorted to
battery.
Expected Engine
Response: Engine will not run, or fuel pump will
continue to run when switch is off.
Possible Causes:
1. Fuel pump relay related
a. Bad fuel pump relay. Primary side open or
shorted.
2. Fuel pump related
a. Fuel pump open or shorted internally.
3. Engine wiring harness related
a. Fuel pump fuse F1 open.
b. Broken or shorted wire in harness. ECU pin
28 to fuel pump relay pin 86. Ignition switch
to fuel pump relay pin 85.
4. ECU related
a. Circuit controlling fuel pump relay damaged.
Code: 61
Source:
Explanation: Denotes the end of fault codes. If
signaled first, no other fault codes are
present.

Troubleshooting Flow Chart

The following flow chart provides an alternative
method of troubleshooting the EFI system. The chart
will enable you to review the entire system in about
10-15 minutes. Using the chart, the accompanying
diagnostic aids (listed after the chart), and any
signaled fault codes, you should be able to quickly
locate any problems within the system.
Section 5B
EFI Fuel System
5B.33
5B