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 using the ECU Data List function of Techstream.
- Turn the ignition switch off and connect Techstream to the DLC3.
- Turn the ignition switch to the ON position. Follow the directions on Techstream 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 ignition switch is turned to the ON position (initial check).
- If the status remains on (OPN DET displayed), check the continuity between the ECU and the sensors, or between EC Us.
- The OPN DET display on Techstream remains on for 1 second after the harness signal changes from momentary interruption (open circuit) to normal condition.
ABS/VSC/TRAC:
DATA LISTTester Display Measurement Item/Range Normal Condition Diagnostic Note FR Speed Open FR speed sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- FL Speed Open FL speed sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- RR Speed Open RR speed sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- RL Speed Open RL speed sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- EFI Open EFI communication open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- Yaw Rate Open Yaw rate sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- Deceleration Open Acceleration sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- Steering Open Steering angle sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- Master Cylinder 1 Open Master cylinder pressure sensor open detection / OPN DET or NORMAL OPN DET: Momentary interruption
NORMAL: Normal- - While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.
Result:
OPN DET display does not change.
HINT:
The connector and/or wire harness will be in momentary interruption (open circuit) if the display changes. Repair or replace the connector and/or wire harness as one of them is faulty.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.