Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Inspection Procedure
2004 Toyota Celica GT, StandardSECTION Inspection Procedure
WARNING: This page is about a different car, the 2003 Lexus RX 300 and 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
- Test drive after the engine warms up. Check that overdrive ON to OFF occurs by operation of the OD switch ON-OFF. If the results are OK, go to the next step. If the results are not OK, check and repair the electronically controlled transmission. See appropriate DIAGNOSIS - U140E & U140F article under AUTOMATIC TRANSMISSION in TRANSAXLE/TRANSMISSION.
- Remove the cruise control ECU with the connector still connected. Turn the ignition switch ON. Disconnect the ECU connector. Connect the positive (+) lead to terminal No. 14 (OD) of the wiring harness side connector of the cruise control ECU and the negative (-) lead to body ground. See CONNECTOR IDENTIFICATION . If voltage is between 10-14 volts, go to the next step. If voltage is not as specified, go to step 5.
- Connect the cruise control ECU connector. Test drive after the engine warms up. Connect the positive (+) lead to terminal No. 6 (ECT) of the ECU connector and the negative (-) lead to body ground when the OD switch is ON and OFF. The results are OK if there is 8-14 volts when the OD switch is ON and if there is below 0.5 volt when the OD switch is OFF. If the results are OK, proceed to the next circuit inspection of the symptom. See PROBLEM SYMPTOM INDEX table. If the results are not OK, go to the next step.
- Check the wiring harness and connector between terminal No. 6 (ECT) of the cruise control ECU and electronically controlled transmission solenoid. If the results are OK, check and replace the cruise control ECU. See CRUISE CONTROL ECU under REMOVAL & INSTALLATION. If the results are not OK, repair or replace the wiring harness or connector.
- Check the wiring harness and connector between terminal No. 14 (OD) of the cruise control ECU and terminal No. 24 (OD1) of the ECM. If the results are OK, check and replace the cruise control ECU. See CRUISE CONTROL ECU under REMOVAL & INSTALLATION. If the results are not OK, repair or replace the wiring harness or connector.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.