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Inspection Procedure

CHECK WIRE HARNESS (MAYDAY ECU ASSEMBLY - MAYDAY BATTERY)

Disconnect the M15 ECU connector.
Disconnect the M13 battery connector.

Measure the resistance of the wire harness side connectors.

Standard resistance

RESISTANCE SPECIFICATIONS

Tester Connection	Specified Condition
M15-2 (BBI+) - M13-1 (BBO+)	Below 1 Ω
M15-9 (BBI-) - M13-2 (BBO-)	Below 1 Ω
M15-2 (BBI+) or M13-1 (BBO+) - Body ground	10 kΩ or higher
M15-9 (BBI-) or M13-2 (BBO-) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR THEN CLEAR HISTORIC DTC

Fig 1: Identifying M15 ECU Connector And M13 Battery Connector

G05284064

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step

REPLACE MAYDAY BATTERY (BACKUP BATTERY)
1. Perform registration (see REGISTRATION ).
2. Check for DTC again.
  OK:
  
  No DTCs output.
NG: REPLACE MAYDAY ECU ASSEMBLY THEN PERFORM REGISTRATION

OK: END (MAYDAY BATTERY IS FAULTY; CLEAR HISTORIC DTC)