Inspection Procedure

HINT:

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

1. Check magnetic clutch circuit. 

   When using hand-held tester: 

   PREPARATION: 

   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON and push the hand-held tester main switch ON.

   CHECK: 

   Read the magnetic clutch current value on the hand-held tester.

   OK: 

   1. Current: 0.8 to 1.0 A 

   When not using hand-held tester: 

   PREPARATION: 

   1. Connect an oscilloscope between terminals CL+ and Cl of the ECM connector.
   2. Start the engine.

   CHECK: 

   Check the waveform between terminals CL+ and CL- of the ECM connector while the engine is idling.

   OK: 

   1. The correct waveform is as shown. 
   Fig 1: Identifying CL Signal Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: Go to step   4 . 

   OK: Go to next step. 

2. Check magnetic clutch. 

   PREPARATION: 

   Disconnect the throttle control motor together with the magnetic clutch connector.

   CHECK: 

   Measure the resistance between terminals 3 and 4 of the throttle control motor with the magnetic clutch.

   Fig 2: Checking Magnetic Clutch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: 

   1. Resistance: 4.2 to 5.2 Ωat 20°C (68°F) 

   NG: Replace throttle control motor with magnetic clutch (See  REPLACEMENT  ). 

   OK: Go to next step. 

3. Check for open and short in harness and connector between magnetic clutch and ECM (See  HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE  ). 

   NG: Repair or replace harness or connector. 

   OK: Go to next step. 

4. Check DTC reoccur. 

   CHECK: 

   1. Clear the DTC (see PRE-CHECK ).
   2. Perform the following steps and check the DTC.
      1. Turn the ignition switch ON.
      2. Start the engine.
      3. Turn the ignition switch OFF and wait 3 seconds.
      4. Turn the ignition switch ON.
      5. Check DTC reoccur.

   OK: 

   1. DTC P1126 is not stored. 

   NG: Replace throttle control motor with magnetic clutch (See  REPLACEMENT  ). 

   OK: Replace ECM (See  ENGINE CONTROL MODULE (ECM)  ).