Lost Communication With Fuel Pump Control Module
What does U0109 mean?
The U0109 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Fuel Pump Control Module. This is a critical severity code.
Common Symptoms
- Check Engine Light illuminated
- Engine cranks but does not start
- Engine stalls and will not restart
- No fuel pump operation
Probable Causes (Ranked by Likelihood)
- Failed fuel pump control module Very High
- CAN bus wiring fault to fuel pump module High
- Corroded module connector at fuel tank Moderate
- Fuel pump module power supply loss Moderate
Step-by-Step Diagnostic Procedure
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Check fuel pump module power and ground at the fuel tank
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Inspect module connector for corrosion -- common near the fuel tank
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Verify CAN bus wiring from module to gateway
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Check if fuel pump runs when directly powered
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Replace fuel pump control module if communication lost
Frequently Asked Questions
Can I drive with code U0109?
Do not drive. Lost communication codes indicate a module has stopped communicating on the vehicle network. The affected system is completely inoperative.
What causes U0109?
The most common cause is a failed module or a wiring issue in the CAN bus network. Failed fuel pump control module is the most likely cause. Power supply, ground, and connector issues should be checked before replacing any module.
Is U0109 expensive to fix?
Repair costs range from $200 - $800 (parts and labor). Wiring repairs are on the lower end, while module replacement is on the higher end. The module may also need to be programmed after replacement.