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.

Check combination meter ECU.
Check : Start the engine and check that the speed meter and tachometer operate normally.

NOTE: This inspection diagnoses the combination meter ECU CPU to determine if it works normally or not.
1. NG : Replace the combination meter ECU.
2. OK : Go to next step.
Check wire harness
Preparation : Disconnect the connector "B11" of back door ECU, see Figure, "C6" of combination meter ECU, see Figure and Figure and "B7" of body ECU, see Figure.

Check
1. Verify continuity between terminals "MPX1" of back door ECU and "MPX2" of combination meter ECU.
2. Verify continuity between terminals "MPX1" of combination meter and "MPX2" of body ECU.
OK : There is continuity in wire harness of both a and b .

NOTE: If there is open in wire harness of either a or b , please repair it.
1. NG : Repair or replace wire harness.
2. OK : Replace the combination meter ECU.