Check The Wiring Harness / Connector; Check The Relay; Ecu Replacement Check - Kubota V3800-CR-TE4 Diagnosis Manual

V3800-CR-TE4,V3800-CR-TIE4, DM

2. Check the Wiring Harness / Connector

1. Remove the connector from the ECU side and check the state
of the continuity between terminal A-90 and (3).
2. Next, check the state of the continuity between terminal B-1 /
B-2 and (4).
Factory
Both have continuity
specification
3. Check the connector for poor connection, engagement and
contact.
Factory
No poor connection, engagement or contact.
specification
OK Go to "3. Check the Relay".
NG Repair or replace the faulty areas.
(1) Terminal +B
(2) Terminal MAHR
(3) Terminal GLRY
(4) Terminal GND

3. Check the Relay

1. After disconnecting the connector of coolant temperature
sensor and connect the dummy resistor (5) as shown in the left
figure, and turn the key switch ON.
Dummy Resistor: 15 to 25 kΩ [Comparable to Approx. −30 to
−20 °C (Approx. −22 to −5 °F)]
2. Measure the voltage between (3) and (4).
Factory When relay is ON: Battery voltage value
specification When relay is OFF: Approx. 0 V
3. Check the state of the continuity between (1) and (2).
Factory When relay is ON: Continuity
specification When relay is OFF: No continuity
4. Measure the resistance in the relay unit (between (3) and (4)).
Factory
Coil resistance value of relay to use
specification
OK Go to "4. ECU replacement check".
NG Relay fault → Replace.
(1) Terminal +B
(2) Terminal MAHR
(3) Terminal GLRY
(4) Terminal GND
(5) Dummy Resistor
(6) Connector

4. ECU Replacement Check

1. Replace the ECU and perform the previous "Check the GLRY
signal".
OK ECU fault → Replace the ECU.
(a) CAN1 Connector
1-S189
COMMON RAIL SYSTEM
(a) Air Heater Relay
A: To Main Air Heater Relay
9Y1200192CRS0732US0
(a) Air Heater Relay
(b) Coolant Temperature Sensor
9Y1200192CRS0733US0
9Y1200192CRS0333US0
KiSC issued 05, 2012 A