Symptom Charts By Components; Gasoline Symptom Charts - Kubota WG1605-E3 Diagnostic Manual

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM

2. SYMPTOM CHARTS BY COMPONENTS

[1] GASOLINE SYMPTOM CHARTS

Checks
Before Using This Section
Important Question to Ask the
Operator
Gasoline Fuel System Check
Visual and Physical Checks
Before using this section you should have performed On Board Diagnostic Checks and determined
that:
• The Control Module and MIL (Malfunction Indicator Lamp) are operating correctly.
• There are no Diagnostic Trouble Codes (DTCs) stored or a DTC exists but without a MIL.
Several of the following symptom procedures call for a careful visual and physical check. The visual
and physical checks are very important. The checks can lead to correcting a problem, without further
checks, that may save valuable time. Most importantly talk to the operator about the failure this may
provide important information about the fault.
• When and how did the operator first notice the fault condition
• What engine speed and load condition did the fault occur at
• Did the fault occur just after or before refueling
• Did the fault occur at start up or shut down
• Did the fault occur at a particular time of day or during the shift
• Did the fault occur in a particular location
• Has there been any recent repair to the engine or vehicle
• Has the fault ever occurred before
• Has there been any new external customer installed devices added to the vehicle and or engine
Verify the customer complaint.
Locate the correct symptoms table.
• Check the items indicated under that symptom.
• Operate the vehicle under the conditions the symptom occurs. Verify HEGO switching between
lean and rich.
IMPORTANT
• Normal HEGO switching indicates the Gasoline fuel system is in closed loop and operating
correctly at that time.
• If a scan tool is available take a snapshot under the condition that the symptom occurs. Go to
Engine Scan Tool Data. List to verify normal sensor values and parameters.
• Check all ECM system fuses and circuit breakers.
• Check the ECM ground for being clean, tight and in its proper location.
• Check the vacuum hoses for splits, kinks and proper connections.
• Check thoroughly for any type of fuel leak or restriction.
• Check for air leaks at all the mounting areas of the intake manifold sealing surfaces.
• Check for proper installation of the Throttle Body assembly.
• Check for fuel leaks at the fuel rail and injectors.
• Check the wiring for the following items:
– Proper connections, pinches or cuts.
• The following symptoms table contains groups of possible causes for each symptom. The order of
these procedures is not important. If the scan tool readings do not indicate the problems, then
proceed in a logical order easiest to check or most likely to cause first.
1-9
Important Preliminary Checks
Action
ECM SYSTEM
KiSC issued 12, 2016 A