Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Check For Intermittent Problems
- CHECK FOR INTERMITTENT PROBLEMS
HINT:
A momentary interruption (open circuit) in the connectors and / or wire harness between the sensors and ECUs can be detected in the ECU data monitor function of the Teachstream.
- Turn the power switch OFF and connect the Techstream to the DLC3.
- Turn the power switch ON (READY). Follow the on screen directions on the Teachstream to display the DATA LIST and select areas where momentary interruption should be monitored.
HINT:
A momentary interruption (open circuit) cannot be detected for 3 seconds after the power switch is turned ON (READY) (initial check).
DIAGNOSTIC CHARTTester Display Measurement Item / Range Normal Condition Diagnostic Note SPD SEN FR FR speed sensor open detection / OPEN or NORMAL NORMAL: Normal condition - SPD SEN FL FL speed sensor open detection / OPEN or NORMAL NORMAL: Normal condition - SPD SEN RR RR speed sensor open detection / OPEN or NORMAL NORMAL: Normal condition - SPD SEN RL RL speed sensor open detection / OPEN or NORMAL NORMAL: Normal condition - YAWRATE SEN Yaw rate sensor open detection NORMAL: Normal condition - DECELE SEN G sensor open detection NORMAL: Normal condition - STEERING SEN Steering sensor open detection NORMAL: Normal condition - M/C SEN 1 Master cylinder pressure sensor 1 open detection NORMAL: Normal condition - M/C SEN 2 Master cylinder pressure sensor 1 open detection NORMAL: Normal condition - STROKE SEN 1 Pedal stroke 1 open NORMAL: Normal condition - FR W/C SEN FR wheel cylinder open NORMAL: Normal condition - FL W/C SEN FL wheel cylinder open NORMAL: Normal condition "- RR W/C SEN RR wheel cylinder open NORMAL: Normal condition - RL W/C SEN RL wheel cylinder open NORMAL: Normal condition - HV COM HV communication open detection NORMAL: Normal condition - ACC SEN Accumulator pressure sensor open detection NORMAL: Normal condition - HINT:
- If the status remains on, check the continuity between the ECU and the sensors, or between ECUs.
- The OPEN display on the Techstream remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
- While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.
Result:
Display does not change.
HINT:
The connector and / or wire harness will have momentary interruptions (open circuit) if the chart fluctuates. Repair or replace connector and / or wire harness as one of them is faulty.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.