U0023 — Low Speed CAN Communication Bus (+) High

What Does U0023 Mean?

U0023 is a diagnostic trouble code indicating: Low Speed CAN Communication Bus (+) High. This code relates to the network communication system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of U0023

⚠️ Check Engine Light (MIL) illuminated
⚠️ Low Speed CAN Communication Bus (+) High not functioning as expected
⚠️ Related system may be in fail-safe mode
⚠️ Multiple warning lights on dashboard

Common Causes

🔍 Faulty Low Speed CAN Communication Bus (+) High
🔍 Wiring or connector issue in Low Speed CAN Communication Bus (+) High circuit
🔍 Related mechanical or electrical fault
🔍 ECM/PCM issue (rare)

Frequently Asked Questions

What does U0023 mean?

U0023 indicates: Low Speed CAN Communication Bus (+) High. The vehicle's computer has detected that the Low Speed CAN Communication Bus (+) High is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code U0023?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with U0023 for extended periods may cause additional problems.

How much does it cost to fix U0023?

Repair costs for U0023 typically range from $100 to $500, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect Low Speed CAN Communication Bus (+) High and related wiring
🔧 Replace faulty Low Speed CAN Communication Bus (+) High

1
Find your vehicle above
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2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

U0023: Low Speed CAN Communication Bus (+) High