Inspection Procedure

HINT:

Read freeze frame data using OBD II scan tool or hand-held tester. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

1. Check voltage between terminal HTS of ECM connector and body ground 

   PREPARATION: 

   1. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
   2. Turn the ignition switch ON.

   CHECK: 

   Measure the voltage between terminal HTS of the ECM connector and body ground.

   OK: 

   Voltage: 9 - 14 V 

   Fig 1: Checking Voltage Terminal HTS Of ECM Connector & Body Ground

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK: Check and replace ECM (See  PROCEDURE  ). 
   2. NG: Go to next step. 
2. Check resistance of heated oxygen sensor heater (See  INSPECTION  ). 
   1. NG: Replace heated oxygen sensor. 
   2. OK: Check and repair harness or connector between EFI main relay (Marking: EFI) and heated oxygen sensor, and heated oxygen sensor and ECM (See  PROCEDURE  ).