U1633 – Invalid or Missing Data for Vehicle Speed.

The ODBII code U1633 indicates that the vehicle’s control module has detected invalid or missing data related to the vehicle speed, which may affect performance or functionality.

The severity of ODBII code U1633 is moderate.

Common Causes For: U1632 U1632: “BCM Communication Failure”

• Faulty vehicle speed sensor
• Damaged wiring or connectors
• Poor ground connection
• Malfunctioning engine control module (ECM)
• Issues with the transmission control module (TCM)
• Faulty ABS module
• Corrupted data communication between modules
• Software glitches or updates needed in the ECM/TCM

Common misdiagnosis for U1633 Invalid or Missing Data for Vehicle Speed.

• Faulty Vehicle Speed Sensor (VSS)
• Malfunctioning Engine Control Module (ECM)
• Wiring issues or shorts in the speed sensor circuit
• Faulty ABS module
• Incorrect tire size or calibration issues
• Transmission problems
• Issues with the instrument cluster
• Faulty or corroded connectors in the speed sensor circuit

Common Troubleshooting Steps

The OBD-II code U1633 indicates an “Invalid or Missing Data for Vehicle Speed.” This code typically points to a communication issue between the vehicle’s control modules, particularly related to the vehicle speed signal. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Other codes may provide more context or indicate related issues.
• Inspect Wiring and Connectors:
• Check the wiring and connectors related to the vehicle speed sensor (VSS) and the modules that communicate with it. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect the speed sensor to the Engine Control Module (ECM) or Transmission Control Module (TCM).
• Test the Vehicle Speed Sensor:
• Locate the vehicle speed sensor and test its output using a multimeter or oscilloscope. Ensure it is producing the correct voltage or signal when the vehicle is in motion.
• If the sensor is faulty, replace it.
• Check the Instrument Cluster:
• If the vehicle has an electronic speedometer, ensure that the instrument cluster is functioning correctly. A malfunctioning cluster can sometimes cause communication issues.
• Inspect the Control Modules:
• Check the ECM and TCM for any signs of damage or failure. Ensure that they are properly communicating with each other.
• If necessary, perform a software update or reprogramming of the control modules.
• Look for Ground Issues:
• Ensure that all ground connections related to the speed sensor and control modules are secure and free of corrosion.
• Scan for Communication Issues:
• Use a scan tool to check for communication errors between modules. If there are issues with the CAN bus or other communication lines, it may affect the vehicle speed data.
• Perform a Visual Inspection:
• Conduct a thorough visual inspection of the engine bay and undercarriage for any signs of damage or wear that could affect the speed sensor or wiring.
• Clear Codes and Test Drive:
• After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code reappears.
• Consult Technical Service Bulletins (TSBs):
• Check for any manufacturer-specific TSBs related to the U1633 code or vehicle speed sensor issues. There may be known fixes or recalls that apply to your vehicle. If the problem persists after following these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis and repair.