Kubota WG1605-E3 Diagnostic Manual page 20

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
• 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:
– Check for faulty fuses or circuit breakers.
– Check for poorly mated electrical connectors.
– Check for connector pin and terminals not fully seated.
– Check for terminal pin damaged or deformation.
– Check poor soldering in the joints and connectors.
– Check for excessive wire strain on the harness.
– Check for burned or damaged wiring.
– Check for recently added customer installed electrical options which may be improperly spliced
into the harness assembly.
• 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, shorted to a ground.
• The Malfunction Indicator Lamp (MIL) circuit or the Diagnostic Test Terminal 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 remain, the ECM is faulty.
1-10
Intermittent
Action
ECM SYSTEM
KiSC issued 12, 2016 A