What Does U0024 Mean?
The negative (-) line of the low-speed CAN bus has an open circuit condition. This prevents proper differential signal transmission between modules on the network.
Common Causes
40%
Broken or severed CAN- wire in harness
25%
Disconnected or backed-out terminal pin in connector
20%
Corroded terminal causing high resistance or open circuit
10%
Failed module with open internal CAN- connection
5%
Damaged splice or repair in CAN- circuit
Diagnostic Steps
1
Step 1: Measure continuity of CAN- circuit from diagnostic port through entire network with ignition off
2
Step 2: Inspect all CAN bus connectors for loose, backed-out, or corroded terminals on CAN- circuit
3
Step 3: Check for broken wires at harness flex points, particularly near doors, seats, and suspension mounting areas
4
Step 4: Verify termination resistors are intact and measure resistance across CAN- to ground (should be high resistance)
5
Step 5: Use wiring diagram to isolate sections of network and test continuity in segments to locate open
Estimated Repair Cost
$200 - $900
Parts + labor, varies by vehicle and location
The negative (-) line of the low-speed CAN bus has an open circuit condition. This prevents proper differential signal transmission between modules on the network.
The most common cause of U0024 (Low Speed CAN Communication Bus (-) Open) is: Broken or severed CAN- wire in harness
Typical repair costs for U0024 range from $200 to $900, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Complete loss of low-speed CAN network functionality will affect comfort and convenience features. Critical safety systems may lose communication depending on vehicle architecture.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U0024 to identify the root cause.
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Quick Info
Category
Network
System
Network Communications
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
