ECU Power Source Circuit: Procedure
WARNING: This page is about a different car, the 2010 Toyota Camry. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)
- Turn the ignition switch off.
- Disconnect the TCM connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C63-8 (E1) - Body ground Always Below 1 Ω
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL)
- Disconnect the TCM connectors.
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition C63-18 (+B) - Body ground Ignition switch ON 11 to 14 V
NG → See step 3
OK → See step 4
- CHECK HARNESS AND CONNECTOR (TCM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)
- Turn the ignition switch off.
- Disconnect the TCM connector.
- Remove the EFI MAIN relay from the engine room junction block assembly.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open)
Tester Connection Condition Specified Condition C63-18 (+B) - EFI MAIN relay terminal 3 Always Below 1 Ω Standard Resistance (Check for Short)
Tester Connection Condition Specified Condition C63-18 (+B) or EFI MAIN relay terminal 3 - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 5
- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
- GO TO ECM POWER SOURCE CIRCUIT (ENGINE CONTROL SYSTEM / SFI SYSTEM). Refer to ECM Power Source Circuit