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Home >> Toyota >> 2002 >> 4Runner Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P1126: Magnetic Clutch Circuit >> Diagnosis & Repair
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Diagnosis & Repair

  1. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step  3.
  2. 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.
  3. 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. 2 (Yellow wire; CL+ circuit) and No. 8 (Blue wire; CL- circuit) at ECM electrical connector E11. 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.
  4. Check resistance of magnetic clutch on throttle control motor. See THROTTLE BODY under IDLE CONTROL SYSTEMS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If magnetic clutch is okay, go to next step. If magnetic clutch is defective, replace throttle body with throttle control motor and magnetic clutch as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
  5. Check for open and short in Yellow and Blue 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.
  6. 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 body with throttle control motor and magnetic clutch as an assembly. See THROTTLE BODY under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
    Fig 1: Identifying Correct Waveform Pattern For Magnetic Clutch
    G00032756Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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