U0127

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: U0127: Lost Communication with Tire Pressure Monitor Module

DTC U0127 - Lost Communication with Tire Pressure Monitor Module

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTICE:
- Turn the power switch off before measuring the resistances of the CAN bus main wires and CAN bus branch wires.
- After the power 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 power 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 power 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.

PROCEDURE

1. CHECK FOR DTC
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Check for DTCs.
HINT: If the CAN MS bus communication error DTC U1002 is output, troubleshoot for U1002 and check for malfunctions in the CAN MS bus.

Result:

B -- GO TO DTC CHART Diagnostic Trouble Code Descriptions (U1002)
A -- Continue to next step.
2. CHECK FOR OPEN IN CAN BUS WIRE (TIRE PRESSURE WARNING ECU BRANCH WIRE)

(a) Disconnect the tire pressure warning ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE TIRE PRESSURE WARNING ECU BRANCH WIRE OR CONNECTOR (CANP, CANN)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - BATTERY AND BODY GROUND)

(a) Disconnect the tire pressure warning ECU connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE TIRE PRESSURE WARNING ECU