Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
- Remove THRO fuse (15-amp) from fuse/relay box at driver's side front corner of engine compartment. See Fig 1. Check THRO fuse. If THRO fuse is okay, reinstall THRO fuse and go to next step. If THRO fuse is defective, replace fuse and check for short in Gray wire between THRO fuse and ECM. See WIRING DIAGRAMS article. ECM is located behind glove box. See Figure. Repair wiring as necessary.
- Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Using voltmeter, check voltage between body ground and terminal No. 6 (Gray wire) at ECM electrical connector E7. See Figure. This is the +BM terminal on ECM. Voltage should 9-14 volts. If voltage is within specification, replace ECM. If voltage is not within specification, repair open or short in wiring harness and electrical connectors between battery, THRO fuse and +BM terminal on ECM. See WIRING DIAGRAMS article.