DTC B1207: Certification ECU Communication Malfunction: Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - BATTERY AND BODY GROUND)

Disconnect the D39 ECU connector.

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

Voltage

Tester Connection	Condition	Specified Condition
D39-1 (+B1) - Body ground	Always	10 to 14 V

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

Resistance

Tester Connection	Condition	Specified Condition
D39-17 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK RESISTANCE OF COMMUNICATION LINE

Disconnect the D13, D39 and D44 ECU connectors.

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

Resistance

Tester Connection	Condition	Specified Condition
D39-27 (MPX1) - D13-7 (MPX2)	Always	Below 1 Ω
D39-28 (MPX2) - D44-7 (MPX1)	Always	Below 1 Ω

Result

Result	Proceed to
Both are OK	A
One is OK	B
Both are NG	C

B → REPLACE CERTIFICATION ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR

C → REPAIR OR REPLACE HARNESS OR CONNECTOR

A → REPLACE CERTIFICATION ECU