Lexus NX: Check For Intermittent Problems

Lexus NX Service Manual / Brake / Brake Control / Dynamic Control Systems / Electronically Controlled Brake System / Check For Intermittent Problems

CHECK FOR INTERMITTENT PROBLEMS

CHECK FOR INTERMITTENT PROBLEMS

HINT:

A momentary interruption (open circuit) in the connectors and/or wire harnesses between the sensors and ECUs can be detected using the Data List function of the Techstream.

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Follow the directions on the Techstream to display the Data List and select areas where momentary interruptions should be monitored.

HINT:

A momentary interruption (open circuit) cannot be detected for 3 seconds after the power switch is turned on (IG) (initial check).
If Error remains displayed for one of the items on the Techstream, check for continuity between the ECU and the item for which Error is displayed.
If a momentary interruption occurs and Error is displayed on the Techstream, Error will remain displayed on the Techstream for 1 second after the circuit returns to normal.

Chassis > ABS/VSC/TRAC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FR Speed Open	Front speed sensor RH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
FL Speed Open	Front speed sensor LH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
RR Speed Open	Rear speed sensor RH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
RL Speed Open	Rear speed sensor LH open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Yaw Rate Open	Yaw rate sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Deceleration Open	Acceleration sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Steering Open	Steering sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Master Cylinder Open	Regulator pressure sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Stroke Open	Brake pedal stroke sensor assembly open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
FR Wheel Cylinder Open	Wheel cylinder pressure sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
Accumulator Open	Accumulator pressure sensor open detection	Error or Normal	Normal: Normal	Error: Momentary interruption
HV Communication Open	Hybrid vehicle communication open detection	Error or Normal	Normal: Normal	Error: Momentary interruption

(f) While observing the screen, gently jiggle the connectors or wire harnesses between the ECUs and sensors, or between ECUs.

OK:

Normal is displayed.

HINT:

If the display changes, this indicates that there has been a momentary interruption (open circuit) in the connector and/or wire harness. In this case, repair or replace the connectors and/or wire harnesses as one of them is faulty.

SEE MORE:

GVIF Disconnected (from Park Assist/Monitoring ECU to EMV/MM Integrated Device) (B1574)

DESCRIPTION DTC No. Detection Item DTC Detection Condition Trouble Area B1574 GVIF Disconnected (from Park Assist/Monitoring ECU to EMV/MM Integrated Device) GVIF disconnected (from parking assist ECU to multi-display assembly) Harness or connector (GVIF cable) Multi-display

Precaution

PRECAUTION PRECAUTIONS WHEN USING TECHSTREAM (a) When using the Techstream with the vehicle power switch off, connect the Techstream to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and the vehicle begins. Then sel

Lexus NX: Check For Intermittent Problems

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Initialization

Calibration

Test Mode Procedure

SEE MORE:

GVIF Disconnected (from Park Assist/Monitoring ECU to EMV/MM Integrated Device) (B1574)

Precaution