What does the vehicle speed CAN signal abnormality 84.9 mean?
4 Answers
It indicates a malfunction where the vehicle speed signal is incorrect, which may cause the engine control unit to fail in determining engine load and vehicle speed sensor data. Additional information: 1. Vehicle Speed Sensor: This device detects the speed of electronically controlled vehicles, providing input signals to the engine control unit for functions such as idle control, torque converter lock-up in automatic transmissions, gear shifting in automatic transmissions, engine cooling fan operation, and cruise control. 2. Installation Location: The vehicle speed sensor signal wire is typically housed in a shielded jacket to eliminate electromagnetic and radio frequency interference from high-voltage ignition wires, car phones, or other electronic devices. This ensures uninterrupted electronic communication and prevents degraded driving performance or other issues.
When I see the issue of abnormal CAN signal for vehicle speed at 84.9, it reminds me that this is usually a fault in the vehicle's electronic communication system. CAN is a communication network inside the car, and if the speed signal is abnormal, especially at the point of 84.9 km/h, it may indicate a problem with the sensor or the speed module. Common causes include faulty wheel speed sensors, aging or short-circuited wiring, or errors in the control module itself. During my frequent vehicle inspections, I often find that such abnormalities can affect the ABS or transmission, as they rely on accurate input data. The value 84.9 might be a specific fault code or a reading threshold, requiring diagnostic tools to decode. It's recommended to first use an OBD scanner to read the fault codes and then proceed with targeted repairs. Don't ignore it to avoid accidents during high-speed driving. Timely handling can prevent chain reactions in other components, such as engine control errors. Remember, safety comes first. If possible, take the vehicle to a professional shop for a comprehensive inspection to prevent the problem from worsening and becoming more costly.
As a DIY car repair enthusiast, I've encountered similar situations multiple times. The abnormal vehicle speed CAN signal at 84.9 km/h usually indicates a signal issue at that speed, which makes me suspect problems with the wheel speed sensor or vehicle speed sensor. I've scanned similar faults using an OBD tool before and found they're mostly caused by poor wiring connections or module software defects. If left unresolved, it could affect the powertrain system, such as causing slower throttle response or inaccurate dashboard readings. My suggestion is to start with simple checks - inspect for foreign objects or corrosion on the sensors, then test the wiring harness voltage. A cost-effective approach is to have a repair shop read the codes to avoid disassembling incorrectly yourself; spending a little money to replace components usually fixes it. Don't delay too long, as it might lead to loss of control during high-speed driving and affect family trips. I believe it's better to address this issue early for both safety and peace of mind.
The vehicle reported an abnormal speed CAN signal of 84.9, which sounds alarming. From my experience handling safety cases, I know such errors can lead to ABS failure or cruise control malfunction. An abnormal speed display of 84.9 in particular may indicate critical system misjudgment. This increases the risk of rear-end collisions or insufficient braking, directly threatening driving safety. I strongly emphasize the need to immediately turn off the engine and pull over to check basic issues like sensor connections or fuse status. Delaying repairs could allow the fault to spread. I recommend scheduling a professional technician to diagnose the root cause with specialized equipment. Do not attempt to drive under these conditions, as it could lead to more severe accidents affecting yourself and others.
