U1637 – Invalid or Missing Data for Vehicle Speed.

The ODBII code U1637 indicates that the vehicle’s control module has detected invalid or missing data related to vehicle speed, which may affect the performance of various systems.

The severity of ODBII code U1637 is moderate.

Common Causes For: U1636 U1636: “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 U1637 Invalid or Missing Data for Vehicle Speed.

• Faulty Vehicle Speed Sensor (VSS)
• Malfunctioning Engine Control Module (ECM)
• Wiring issues or short circuits
• Faulty Transmission Control Module (TCM)
• Incorrect tire size or calibration issues
• Problems with the ABS module
• Issues with the instrument cluster
• Faulty or corroded connectors and terminals

Common Troubleshooting Steps

The OBD-II code U1637 indicates an “Invalid or Missing Data for Vehicle Speed.” This code typically points to a communication issue between the vehicle’s modules, particularly related to the vehicle speed sensor (VSS) or the data being transmitted over the vehicle’s network. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing related codes can help in diagnosing the root cause.
• Inspect Vehicle Speed Sensor (VSS): **Visual Inspection: Check the VSS for any physical damage, loose connections, or corrosion at the connector.
• **Wiring Check: Inspect the wiring harness for any frays, breaks, or shorts that could affect the signal.
• **Testing: Use a multimeter to test the VSS for proper voltage and resistance according to the manufacturer’s specifications.
• Check Module Communication: **CAN Bus Inspection: Ensure that the Controller Area Network (CAN) bus is functioning properly. Look for any damaged wiring or poor connections.
• **Scan Tool Communication: Use a scan tool to check if other modules can communicate with the engine control module (ECM) and the transmission control module (TCM).
• Inspect Ground Connections: Ensure that all ground connections related to the VSS and the ECM are clean, tight, and free of corrosion. Poor grounding can lead to communication issues.
• Check for Software Updates: Verify if there are any software updates available for the vehicle’s modules. Sometimes, manufacturers release updates to fix known issues.
• Test the ECM/TCM: If the VSS and wiring are functioning correctly, the issue may lie within the ECM or TCM. Testing or reprogramming these modules may be necessary.
• 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 TSBs related to the U1637 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose complex issues. By following these troubleshooting steps, you should be able to identify and resolve the cause of the U1637 code. Always refer to the vehicle’s service manual for specific procedures and specifications.