Diagnosis & Repair
WARNING: This page is about a different car, the 2002 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
- If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step 3.
- Connect hand-held tester to Data Link Connector (DLC) No. 3 at driver's side of instrument panel. See Figure. Turn ignition on and then turn hand-held tester on. Using hand-held tester, read magnetic clutch current value. If magnetic clutch current is .8-1.0 amp, go to step 4. If magnetic clutch current reading is not .8-1.0 amp, go to step 6.
- Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Waveform pattern should be checked for magnetic clutch at ECM. Connect oscilloscope between terminal No. 19 (Blue wire; CL- circuit) and No. 29 (Green wire; CL+ circuit) at ECM electrical connector E5. For ECM electrical connector terminal identification, see Figure. Start engine and allow engine to idle. Note magnetic clutch waveform pattern with engine idling. Ensure magnetic clutch waveform pattern is properly displayed. See Fig 1. If magnetic clutch waveform pattern is as shown, go to next step. If magnetic clutch waveform pattern is not as shown, go to step 6.
- Disconnect electrical connector at throttle control motor located on side of throttle body. See Figure. Using ohmmeter, check resistance between terminals No. 3 and 4 on electrical connector on throttle control motor for the magnetic clutch. See Figure. Resistance should be 4.2-5.2 ohms at 68°F (20°C). If resistance is within specification, go to next step. If resistance is not within specification, replace throttle control motor with magnetic clutch as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
- Check for open and short in Blue and Green wires and electrical connectors between throttle control motor and ECM. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary.
- Using Toyota hand-held tester or scan tool, clear DTCs from ECM. Start engine and allow engine to idle. Turn ignition off and wait 3 seconds. Turn ignition on and then use Toyota hand-held tester or scan tool to check for DTCs. If DTC P1126 does not exist, replace ECM. ECM is located behind glove box. See Figure. If DTC P1126 exists, replace throttle control motor with magnetic clutch as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.