Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Ecu power source circuit
Toyota Corolla (E120): Ecu power source circuit
Circuit description
This circuit provides power to operate the tvip ecu.
Wiring diagram

Inspection procedure
1 Check fuse (ecu–b)

- Remove the fuse from the instrument panel j/b.
- check the continuity of the fuse.
Standard: continuity


2 Check tvip ecu

- Disconnect the tvip ecu connector.
- measure the voltage between the terminals of the ecu connector, as shown in the illustration and table.
Standard:



3 Check wire harness (tvip ecu body ground)

- Disconnect the tvip ecu connector.
- check the connector on the harness side, as shown in the illustration and table.
Standard:



Check and replace tvip ecu
Other materials:
Pre–check
1. Srs warning light check
Turn the ignition switch to the on position and check that
the srs warning light lights up.
check that the srs warning light goes out after approx.
6 Seconds.
Hint:
when the ignition switch is at on and the srs warning
light remains on or flashes, the ...
Circuit description
The intake air temperature (iat) sensor, mounted on the mass
air flow (maf) sensor, monitors the intake air temperature. The
iat sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermisto ...
Fail–safe chart
If any of the following codes is recorded, the ecm enters the fail–safe mode.
Check for intermittent problems
Hand–held tester only:
by putting the vehicle’s ecm in the check mode, the 1 trip detection logic is
possible instead of the
2 trip detection logic, and the sensitivity to de ...


