DTC U0127: Lost Communication with Tire Pressure Monitor Module: Procedure

1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the CAN main wire and CAN branch wire.
   WARNING:

   Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected, refer to INITIALIZATION .

NEXT: Go to next step 

1. Disconnect the D33 tire pressure monitor ECU connector.
   Fig 1: Identifying D33 Tire Pressure Warning ECU Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   D33-6 (CANP) - D33-12 (CANN)	Ignition switch off	54 to 69 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Tire Pressure Monitor ECU)

NG → REPAIR OR REPLACE TIRE PRESSURE MONITOR ECU CAN BRANCH WIRE OR CONNECTOR (CANP, CANN) 

OK: Go to next step 

1. Connect the cable to the negative (-) battery terminal.
   Fig 2: Identifying Tire Pressure Warning D33 ECU Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   NOTE:

   When disconnecting the cable, some systems need to be initialized after the cable is reconnected, refer to INITIALIZATION .

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D33-7 (GND) - Body ground	Always	Below 1 Ω

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   D33-1 (IG) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Rear view of wire harness connector (to Tire Pressure Monitor ECU)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4