Inspection Procedure

WARNING: This page is about a different car, the 2009 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Turn the ignition switch off before measuring the resistance of the main CAN bus wires and the CAN Bus branch wire.
After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If any doors need to be opened in order to check the connectors, open the doors and leave them open.

HINT:

Operating the ignition switch, any other switches, or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below will help determine the cause of the malfunction.

CHECK CAN BUS WIRE FOR DISCONNECTION (POWER STEERING ECU BRANCH WIRE)

Turn the ignition switch off.
Disconnect the power steering ECU connector.
Measure the resistance according to the value (s) in the table below.

Standard Resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
E32-1 (CANH) - E32-7 (CANL)	Ignition switch off	54 to 69 Ω

NG: REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (POWER STEERING ECU BRANCH WIRE)

Fig 1: Identifying E32 Power Steering ECU Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to Next Step

CHECK WIRE HARNESS (POWER STEERING ECU - BATTERY AND BODY GROUND)

Disconnect the power steering ECU connectors.

Measure the resistance according to the value (s) in the table below.

Standard Resistance

STANDARD RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
A75-2 (PGND) - Body ground	Always	Below 1 Ω

Measure the voltage according to the value (s) in the table below.

Standard Voltage

STANDARD VOLTAGE SPECIFICATION

Tester Connection	Condition	Specified Condition
A75-1 (PIG) - Body ground	Always	10 to 14 V
E32-6 (IG) - Body ground	Ignition switch ON	10 to 14 V

Result

RESULT REFERENCE

Result	Proceed to
OK (for 2AZ-FE)	A
OK (for 2ZR-FE)	B
NG	C

B: REPLACE POWER STEERING ECU (for 2ZR-FE) (See POWER STEERING ECU (FOR 2ZR-FE) )

C: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 2: Identifying A75 And E32 Power Steering ECU Connector

A: REPLACE POWER STEERING ECU (for 2AZ-FE) (See POWER STEERING ECU (FOR 2AZ-FE) )