DTC U2303 Immobilizer Unknown Signal Received (4JJ3 with DPD)

For the diagnostic type, refer to the diagnostic type list in the DTC description.

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Diagnostic system check-engine controls".

2. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Central gateway control system inspection.

No

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 with DPD) intermittent conditions of engine".

3. Central gateway control system inspection

1) Perform the central gateway control system inspection.

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) diagnostic system check - central gateway controls".

Procedure completion

=>Go to Wireless access module communication verification.

4. Wireless access module communication verification

1) Verify that communication can be established with the wireless access module using a scan tool. Can communication with the wireless access module be established?

Yes

=>Go to Immobilizer-related DTC check.

No

Go to Diagnostic system check-wireless access module.

Refer to "71.Security and Locks Control 10S.Troubleshooting(Wireless Access Module (Mid-version/Lo-version [Except Passive Entry and Start System])) Diagnostic system check-Wireless Access Module (Mid-version/Lo-version [Except Passive Entry and Start System])".

Refer to "71.Security and Locks Control 10S.Troubleshooting(Wireless Access Module (Hi-version [Passive Entry and Start System])) Diagnostic system check-Wireless Access Module (Hi-version[Passive Entry and Start System])".

5. Immobilizer-related DTC check

1) Observe the immobilizer-related DTC with a scan tool. Is an immobilizer-related DTC that starts with B set?

Yes

Go to the applicable DTC diagnosis.

No

=>Go to Chassis CAN communication circuit inspection.

6. Chassis CAN communication circuit inspection

1) Perform the Chassis CAN communication circuit inspection

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) chassis CAN communication circuit inspection".

Procedure completion

=>Go to CAN circuit resistance check.

7. CAN circuit resistance check

1) Turn OFF the ignition switch.

2) Measure the resistance between the CAN High circuit and the CAN Low circuit (pins 14 and 16 of C9) from the backside of the ECM harness connector with a DMM. Is the resistance within the specified range?

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Value: 50 to 70 Ω

Yes

=>Go to ECM harness connector inspection.

No

=>Go to Inspection for open circuit in central gateway control unit CAN circuit.

8. Inspection for open circuit in central gateway control unit CAN circuit

1) Inspect the CAN circuit between the ECM (pins 14 and 16 of C9) and the central gateway control unit (pins 5 and 6 of B41) for an open circuit or high resistance. Is the result normal?

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Inspection for short circuit in central gateway control unit CAN circuit.

No

Repair the circuit as necessary.

=>Go to Repair verification.

9. Inspection for short circuit in central gateway control unit CAN circuit

1) Inspect for a short together in the CAN circuits between the ECM (pins 14 and 16 of C9) and the central gateway control unit (pins 5 and 6 of B41). Is the result normal?

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

10. ECM harness connector inspection

1) Inspect for poor connections at the ECM harness connector (pins 14 and 16 of C9). Is the connection status normal?

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to ECM replacement.

No

Repair the connections as necessary.

=>Go to Repair verification.

11. ECM replacement

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM setting".

Procedure completion

=>Go to Repair verification.

12. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool.