what should I do if my Toyota Corolla E210 (2019-2024) has a check engine light with code P0700?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect Transmission Fluid

• Locate the transmission dipstick (if equipped).
• Remove the dipstick, wipe clean, and reinsert it fully.
• Pull the dipstick out again to check fluid level; add fluid if low.
• Inspect fluid for burnt smell or discoloration; if burnt, plan for a transmission fluid change.

3. Check Wiring and Connectors

• Locate the TCM and visually inspect all wiring harnesses and connectors.
• Look for any signs of corrosion, damage, or loose connections.
• Repair or replace any damaged wiring or connectors as necessary.

4. Test the Transmission Control Module

• Use a multimeter to check for proper voltage at the TCM connectors.
• Consult a repair manual for specific voltage specifications.
• If voltages are incorrect, consider replacing the TCM.

5. Inspect Transmission Range Sensor

• Locate the transmission range sensor on the transmission.
• Disconnect the sensor and inspect the connector for corrosion.
• Use a multimeter to test the sensor output according to manufacturer specifications.
• Replace the sensor if it fails the tests.

6. Reassemble and Reconnect

• Reconnect any connectors and wiring that were removed or inspected.
• Reconnect the negative battery terminal.
• Clear any stored codes using the OBD-II scanner.