What Does P1648 Mean?
A component on the CAN bus communication system has failed or is not responding. This indicates a hardware failure of a control module or the bus network itself rather than just a communication error.
Safety Warning
Vehicle may not start, experience sudden loss of power, or have critical safety systems disabled. Should not be driven until repaired.
Common Causes
30%
Failed Engine Control Module or Transmission Control Module
25%
Damaged or corroded CAN bus wiring or connectors
20%
Shorted or open CAN High or CAN Low circuit
15%
Failed Body Control Module or other networked module
10%
Water intrusion or corrosion in control module
Diagnostic Steps
1
Step 1: Monitor live CAN bus data to identify which module(s) are not communicating
2
Step 2: Inspect CAN bus wiring harness for physical damage, shorts to ground/power, or opens
3
Step 3: Measure CAN High and CAN Low voltages at multiple points (should be approximately 2.5V at rest, with opposite fluctuations during communication)
4
Step 4: Check terminating resistors across CAN High and CAN Low (should measure approximately 60 ohms with all modules connected)
5
Step 5: Isolate suspect modules one at a time to identify failed component
Estimated Repair Cost
$200 - $1,500
Parts + labor, varies by vehicle and location
A component on the CAN bus communication system has failed or is not responding. This indicates a hardware failure of a control module or the bus network itself rather than just a communication error.
The most common cause of P1648 (CAN-Bus System Component Failure) is: Failed Engine Control Module or Transmission Control Module
Typical repair costs for P1648 range from $200 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may not start, experience sudden loss of power, or have critical safety systems disabled. Should not be driven until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1648 to identify the root cause.
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Quick Info
Category
Powertrain
System
CAN Bus Communication Network
Difficulty
Type
Manufacturer
Recommended Tools
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