Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After confirming DTC P0115, use Toyota hand-held tester or scan tool to access CURRENT DATA to confirm engine coolant temperature. If ECT sensor value displayed on hand-held tester or scan tool is always -40°F (-40°C), ECT sensor circuit may be open. If ECT sensor value displayed on hand-held tester or scan tool is always 284°F (140°C), ECT sensor circuit may be shorted. Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

For diagnosis and repair procedure, see Fig 2-Fig 4 .

For ECT sensor circuit wiring diagram, see Fig 1. For location of emission related components, see Figure.

For ECM location, see Figure. For ECM connector terminal view, see Figure.

For testing of systems or components, see SYSTEM & COMPONENT TESTING - 4-CYLINDER article. For removal and installation of components, see REMOVAL & INSTALLATION - 4-CYLINDER article.

Fig 1: ECT Sensor Circuit Wiring Diagram

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: DTC P0115 Diagnostic Procedure (Steps 1-2)

Fig 3: DTC P0115 Diagnostic Procedure (Steps 3-4)

Fig 4: DTC P0115 Diagnostic Procedure (Step 5)