Serial Communication Link Malfunction
The P0600 code means the vehicle's onboard diagnostic system has detected: Serial Communication Link Malfunction. This is a serious severity code.
- Keep driving?
- Limited driving only
- DIY difficulty
- medium
- Estimated cost
- $100-$250 for battery; $200-$600+ for wiring or module diagnosis
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What Are the Symptoms of P0600?
- Multiple warning lights on dashboard
- Communication errors between control modules
- Various system malfunctions (transmission, ABS, body control)
- Vehicle may enter limp mode
What Causes P0600? (Most Likely First)
- Low system voltage causing CAN bus communication errors High
- Damaged CAN bus wiring or connector High
- Faulty control module dragging down the CAN bus Moderate
- Corroded ground connections affecting module communication Moderate
Can I Still Drive with P0600?
Limited driving only. P0600 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Can a bad battery cause P0600?
Yes. Low or unstable voltage is a very common trigger for serial communication codes. Always check the battery and charging system before pursuing expensive module or wiring repairs.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0600?
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Check battery voltage and charging system first: low voltage is the most common cause of serial communication errors.
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Inspect CAN bus connectors and wiring under the hood and at the data link connector (OBD-II port) for damage.
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Scan all modules for additional codes. A failing module will often set codes in multiple systems.
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Test CAN bus resistance between pins 6 and 14 of the OBD-II port: should be approximately 60 ohms (two 120-ohm terminating resistors in parallel).
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P0600?
- Any vehicle: most common when battery is low or failing
- Ford vehicles (CAN bus issues on early 2000s)
- GM vehicles
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