Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before ECU replacement, see HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS to ensure all communication line/bus/wire issues have been eliminated as a cause of communication loss.

NOTE: With this inspection, driver door ECU CPU can be diagnosed, so it can be determined if it works normally or not.

Check driver door ECU.
Check if the driver door window glass auto up.
1. NG : Replace the driver door ECU.
2. OK : Go to next step.
Check wire harness.
Preparation : Disconnect ECU connectors, see Figure. For "B6" of body ECU, see Figure, "D22" of driver door ECU, see Figure, and "F18" of passenger door ECU, see Figure.

Check
1. Verify continuity between terminals MPX1 of body ECU and MPX2 of driver door ECU.
2. Verify continuity between terminals MPX1 of driver door ECU and MPX2 of passenger door ECU.
  NOTE: If there is OPEN in wire harness of either a or b , please repair it.
OK - there is continuity in wire harness of both a and b .
1. NG : Repair or replace wire harness.
2. OK : Replace the driver door ECU.