DTC U2303 Immobilizer Unknown Signal Received (4JJ3 without 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 without 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 Wireless access module communication verification.

No

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 without DPD) intermittent conditions of engine".

3. 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])".

4. 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 CAN circuit resistance check.

5. CAN circuit resistance check

1) Turn OFF the ignition switch.

2) Measure the resistance between the CAN High circuit and the CAN Low circuit of the DLC (pins 6 and 14 of C19) with a DMM. Is the resistance within the specified range?

Note

  • The parallel resistance of the 120 Ω resistor in the ECM and the 120 Ω resistor in the instrument panel cluster is 60 Ω.

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

Refer to "RHD Controller Area Network (Except 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 Inspect for open circuit in wireless access module CAN circuit.

6. Inspect for open circuit in wireless access module CAN circuit

1) Inspect the CAN circuit between the ECM (pins 14 and 16 of C9) and the wireless access module (pins 19 and 20 of B15 for models with Hi-Version, pins 5 and 12 of B13 except for models with Hi-Version) for an open circuit or high resistance. Is the result normal?

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

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

Yes

=>Go to Inspect for short circuit in wireless access module CAN circuit.

No

Repair the circuit as necessary.

=>Go to Repair verification.

7. Inspect for short circuit in wireless access module CAN circuit

1) Inspect for a short together in the CAN circuits between the ECM (pins 14 and 16 of C9) and the wireless access module (pins 19 and 20 of B15 for models with Hi-Version, pins 5 and 12 of B13 except for models with Hi-Version). Is the result normal?

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

Refer to "RHD Controller Area Network (Except 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.

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

Refer to "RHD Controller Area Network (Except 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.

9. ECM replacement

Note

  • Perform programming after replacing the ECM.

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM setting".

Procedure completion

=>Go to Repair verification.

10. 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.