Kubota WG1605-E3 Diagnostic Manual page 29

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM
Checks
DEFINITION: The problem may or may not turn ON the Malfunction Indicator Lamp (MIL), or store a Diagnostic Trouble Code (DTC).
Preliminary Checks
Faulty Electrical Connections, or
Wiring
Operational Test
Intermittent Malfunction Indicator
Lamp (MIL)
Loss of DTC Memory
Additional Checks
• Refer to Important Preliminary Checks.
• Do not use the DTC tables, if a fault is an intermittent, the use of the DTC tables may result in the
replacement of good parts.
• Faulty electrical connections, or wiring, can cause most intermittent problems.
• Check the suspected circuit for the following conditions:
– Faulty fuse, or circuit breaker
– Connectors poorly mated
– Corrosion or loose pins in the connectors
– Terminals not fully seated, in the connector (backed out)
– Terminals not properly formed, or damaged
– Terminal to wire joints poorly connected
– Terminal tension, insufficient
– Wire strain from improper wire routing
– Burned or damaged wires from contacting hot surfaces or rotating devices
• Improper splicing method used when optional equipment is installed to the vehicle.
• Carefully remove all the connector terminals in the problem circuit, in order to ensure the proper
contact tension. If necessary, replace all the connector terminals in the problem circuit, in order to
ensure the proper contact tension.
• Checking for poor terminal, to wire connections, requires removing the terminal from the connector
body.
If a visual and physical check does not locate the cause of the problem, drive the vehicle with a scan
tool. When the problem occurs, an abnormal voltage or scan reading indicates the problem may be in
that circuit.
The following components can cause intermittent MIL, and no DTC(s):
• A defective relay Control Module driven solenoid, or a switch that can cause electrical system
interference. Normally, the problem will occur when the faulty component is operating.
• The improper installation of electrical devices, such as lights, 2-way radios, electric motors, etc.
• The ignition, secondary voltage, is shorted to a ground.
• The Malfunction Indicator Lamp (MIL) circuit, or the Diagnostic Test Terminal, is intermittently
shorted to ground.
• The Control Module grounds.
To check for the loss of the DTC Memory:
1. Disconnect the TMAP sensor.
2. Idle the engine, until the Malfunction Indicator Lamp illuminates.
The ECM should store a TMAP DTC. The TMAP DTC should remain in the memory, when the ignition
is turned OFF. If the TMAP DTC does not store and remains, the ECM is faulty.
1-19
Intermittent
Action
ECM SYSTEM
KiSC issued 12, 2016 A