LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2002 >> Prius >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Component Testing - 4-Cylinder >> Computerized Engine Controls >> Starter Signal Circuit >> Corolla
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Starter Signal Circuit: Corolla

  1. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step  5.
  2. Connect hand-held tester to data link connector No. 3 at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester on. Read STA signal display on hand-held tester with ignition on, and with ignition switch in START position and engine cranking. STA signal display should read OFF with ignition on, and ON with ignition switch in START position. If STA signal display is not as specified, go to next step. If STA signal display is as specified, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
  3. Check for open in Black/White wire (starter signal wire) and electrical connectors between starter relay and terminal No. 11 at Engine Control Module (ECM) electrical connector E6 on 3-speed A/T and M/T models, or terminal No. 11 at ECM electrical connector E9 on 4-speed A/T models. See WIRING DIAGRAMS article. ECM is located behind stereo on instrument panel, just in front of center console. For illustration of ECM location, see THEORY & OPERATION article. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower and may be marked as ST relay. For ECM electrical connector terminal identification, see Figure and Figure .
  4. If wiring harness or electrical connector is defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
  5. Remove necessary components for access to Engine Control Module (ECM). See ENGINE CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article. Remove bolts from ECM so electrical connectors can be accessed on ECM.
  6. Note ECM electrical connector terminals. See Figure and Figure . On 3-speed A/T and M/T models, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E6 with ignition switch in START position and engine cranking. On 4-speed A/T models, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E9 with ignition switch in START position and engine cranking. On all models, this is the STA terminal at ECM.
  7. On all models, voltage should be 6 volts or more. If voltage is not within specification, go to next step. If voltage is within specification, diagnose by symptom. See TROUBLE SHOOTING - NO CODES article.
  8. Check for open and short in Black/White wire and electrical connectors between starter relay and terminal No. 11 at ECM electrical connector E6 on 3-speed A/T and M/T models, or terminal No. 11 at ECM electrical connector E9 on 4-speed A/T models. See WIRING DIAGRAMS article. This is the starter signal wire. Starter relay is located in fuse/relay box at driver's side front corner of engine compartment, just in front of strut tower and may be marked as ST relay.
  9. If wiring harness or electrical connector is defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM.
scientia non olet · About LEMON Manuals