Inspection Procedure
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
For circuit wiring diagram, see Fig 1.
- Connect the OBD II scan tool or hand-held tester to the DLC3. DLC3 is located under the left side of the instrument panel. See Figure. Turn the ignition switch ON and push the hand-held tester main SW ON. Select the item KEY TYPE in the DATA LIST and read it's value displayed on the hand-held tester. It is OK if it reads: Key type / MASTER or SUB. If it is OK, the malfunction occurs in the engine including the engine control module (ECM). If the results are not good, go to the next step.
- Check whether the engine starts with other keys for the vehicle. If the results are OK, go to the next step. If the results are not good, go to step 4.
- Reregister or replace the key that does not start the engine and then check whether the engine starts. If the engine starts then the system is OK. If the engine does not start, the transponder chip of a specific key is defective and replace the key.
- Check the continuity between terminal 1 (+B) of the transponder key coil connector and body ground. See Fig 2. If there is continuity, go to the next step. If there is not continuity, repair or replace the harness and connector.
- Check the continuity between terminal 1 (GND) of the transponder key coil connector and body ground. See Fig 2. If there is continuity, go to the next step. If there is not continuity, repair or replace the harness and connector.
- Check the wiring harness.
- Disconnect the transponder key amplifier and ECM connectors.
- Check the continuity between each terminal of the transponder key amplifier vehicle's side connector and the ECM vehicle's side connector. See Fig 2-Fig 4 . If the results are OK, go to the next step. If the results are not good, repair or replace the harness and connector.
- Check that the engine will start when connected to a new or normal transponder key amplifier. If the engine starts then the system is normal. If the engine does not start, replace the engine control module (ECM).