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Home >> Toyota >> 2004 >> Matrix Base, FWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 79 (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 SC 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check ETCS fuse (15-amp) located in engine compartment fuse/relay box on driver's side wheel well. 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. Backprobing connector, measure voltage between ECM connector E4 terminal No. 3 (Brown wire) and terminal No. 7 (Black/Red wire) at ECM E6 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, ETCS fuse and ECM. See WIRING DIAGRAMS article. Repair wiring as necessary.
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