Problem Confirmation Test

Abnormality detection ability in the test mode is increased compared to that in the normal mode, so that when momentary interruptions or momentary shorts occur in the engine control module (ECM) signal circuits (G, NE, THW, THA, PIM or VTA) listed below, the appropriate diagnostic trouble code is output.

CODE NUMBER 13: G, NE signal circuit (No. 2)
CODE NUMBER 22: Engine coolant temperature sensor circuit
CODE NUMBER 24: Intake air temperature sensor circuit
CODE NUMBER 31: Manifold absolute pressure sensor circuit
CODE NUMBER 41: Throttle position sensor circuit

Accordingly, when the diagnostic trouble codes shown in this list are output during the diagnostic trouble code check, and inspection of the appropriate circuits reveals no abnormality, perform the "Test For Intermittent Problems" as described below.
By performing the "Test For Intermittent Problems", the place where momentary interruptions or momentary shorts are occurring due to poor contacts can be isolated.


TEST FOR INTERMITTENT PROBLEMS
1. CLEAR DIAGNOSTIC TROUBLE CODES.
For information, see "How To Clear Diagnostic Trouble Codes" under Computers and Control Systems/System Diagnosis.

2. SET TEST MODE.



a. With the ignition switch OFF, connect the terminals TE2 and E1 of the data link connector (DLC1) using a jumper wire (or SST 09843-18020).
b. Start the engine and check to see the malfunction indicator lamp ("CHECK" engine lamp) goes OFF.
- If the malfunction indicator lamp does not go OFF after the engine is started, check thoroughly for faulty contacts, etc., then try again. If the malfunction indicator lamp still does not go OFF, replace the ECM.

3. PERFORM A SIMULATION TEST.






- Using symptom simulation methods, apply vibration to and pull lightly on the wire harness, connector or terminals in the circuit indicated by the malfunction code.
- In this test, if the malfunction indicator lamp lights up, it indicates that the place where the wire harness, connector or terminals being pulled or vibrated has faulty contact. Check that point for loose connections, corrosion on the terminals, poor fit or other problems and repair as necessary.

NOTE: If a Toyota Hand-Held Tester is available, see connection information under Computers and Control Systems/System Diagnosis/"Normal Scan Data Values".