Starter Signal Circuit: 4Runner

If using scan tool, go to next step. If scan tool is not available, go to step 5.
Connect scan tool to data link connector No. 3. See Fig 9. Turn ignition on and then turn scan tool on. Read STA signal display on scan tool 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.
Check for open in Black/White wire in wiring harness and electrical connectors between ECM and splice No. 121. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. ECM is located behind glove box. For illustration of ECM location, see THEORY & OPERATION article. Splice No. 121 is located behind driver's side of instrument panel. See Fig 1.

Fig 1: Locating Splice No. 121 (4Runner)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If wiring harness, electrical connector or splice are defective, repair as necessary. If wiring harness, electrical connectors and splice 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.
Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. Note ECM electrical connector terminals. See Figure and Figure . On Calif. emission vehicles, using voltmeter, check voltage body ground and terminal No. 7 (Black/White wire) at ECM electrical connector E8 with ignition in START position and engine cranking. See Figure. On all except Calif. emission vehicles, using voltmeter, check voltage between body ground and terminal No. 11 (Black/White wire) at ECM electrical connector E8 with ignition in START position and engine cranking. See Figure. On all models, this is the STA terminal at ECM.
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.
Check for open in Black/White wire in wiring harness and electrical connectors between ECM and splice No. 121. See appropriate wiring diagram in STARTERS article in STARTING & CHARGING SYSTEMS. Splice No. 121 is located behind driver's side of instrument panel. See Fig 1.
If wiring harness, electrical connector or splice are defective, repair as necessary. If wiring harness, electrical connectors and splice 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.