Yamaha 2004 YP400, Service Manual, Page: 325 / 417

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FI
FUEL INJECTION SYSTEM
Fault code No. Er-2 Symptom No signals are received from the ECU within the specified duration.
Used diagnostic code No. – –
Order Inspection operation item and
probable cause Operation item and countermeasure Reinstatement
method
1 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Main wiring harness ECU coupler
Sub-wire harness coupler
Reinstated if nor-
mal signal is
received from the
ECU when the
main switch is set
to ON.
2 Open or short circuit in wiring har-
ness and/or sub lead. Repair or replace if there is an open or short circuit.
Between meter coupler and ECU coupler
yellow/blue – yellow/blue
3 Malfunction in meter Replace the meter.
4 Malfunction in ECU Replace the ECU.
Fault code No. Er-3 Symptom Data from the ECU cannot be received correctly.
Used diagnostic code No. – –
Order Inspection operation item and
probable cause Operation item and countermeasure Reinstatement
method
1 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Main wiring harness ECU coupler
Sub-wire harness coupler
Reinstated if nor-
mal signal is
received from the
ECU when the
main switch is set
to ON.
2 Open or short circuit in wiring har-
ness and/or sub lead. Repair or replace if there is an open or short circuit.
Between meter coupler and ECU coupler
yellow/blue – yellow/blue
3 Malfunction in meter Replace the meter.
4 Malfunction in ECU Replace the ECU.
Fault code No. Er-4 Symptom Non-registered data has been received from the meter.
Used diagnostic code No. – –
Order Inspection operation item and
probable cause Operation item and countermeasure Reinstatement
method
1 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
If there is a malfunction, repair it and connect it
securely.
Main wiring harness ECU coupler
Sub-wire harness coupler
Reinstated if nor-
mal signal is
received from the
ECU when the
main switch is set
to ON.
2 Open or short circuit in wiring har-
ness and/or sub lead. Repair or replace if there is an open or short circuit.
Between meter coupler and ECU coupler
yellow/blue – yellow/blue
3 Malfunction in meter Replace the meter.
4 Malfunction in ECU Replace the ECU.