C1438

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1438/59: Lost Communication with HV ECU
C1438/59 - Lost Communication with HV ECU

DESCRIPTION

The skid control ECU receives signals from the hybrid vehicle control ECU via the CAN communication system.

WIRING DIAGRAM

Refer to DTCs U0073/94, U0123/62, U0124/95, U0126/63 and U0293/59 Electronically Controlled Brake System.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC Check For Intermittent Problems.

ABS/VSC/TRAC

OK:

There are no momentary interruptions.

HINT
Perform the above inspection before removing the sensor and connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - HYBRID VEHICLE CONTROL ECU)
OK -- Continue to next step.

2. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the ignition switch to ON (READY).

(d) Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.

(e) Check that no CAN communication system DTC is output (w/ Smart Key System: Diagnosis System, w/o Smart Key System: Diagnosis System).

(f) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:

D -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting

C -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) How to Proceed With Troubleshooting

B -- REPLACE SKID CONTROL ECU Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

3. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - HYBRID VEHICLE CONTROL ECU)

(a) Turn the ignition switch off.

(b) Repair or replace the harness or connector.

(c) Check for any momentary interruption between the skid control ECU and the hybrid vehicle control ECU Check For Intermittent Problems.

(d) Confirm that there is no momentary interruption.

NEXT -- Continue to next step.

4. RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(c) Turn the ignition switch to ON (READY).

(d) Drive the vehicle at a speed of 15 km/h (9 mph) or more for 10 seconds or more.

(e) Check that no CAN communication system DTC is output (w/ Smart Key System: Diagnosis System, w/o Smart Key System: Diagnosis System).

(f) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result: