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Home >> Toyota >> 2004 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 38 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P1127: Electronic Throttle Control System (ETCS) Actuator Power Source Circuit Malfunction >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check ETCS fuse (15-amp) from fuse/relay box located at passenger side of firewall in engine compartment. If ETCS fuse is okay, go to next step. If ETCS fuse is blown, check for short circuit in wiring harness between ETCS fuse and ECM. See WIRING DIAGRAMS article. Repair wiring as necessary.
  2. Access ECM under protective cover, behind left headlight in engine compartment. Backprobing, measure voltage between ground and terminal No. 7 (Blue/White wire) at ECM E3 connector. See Figure. If voltage is 9-14 volts, replace ECM and retest. If voltage is not 9-14 volts, check circuits in wiring harness between battery voltage, ETCS fuse and ECM. See WIRING DIAGRAMS article. Repair wiring as necessary.
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