Fuel Pump A Control Circuit High
The P0629 code means the vehicle's onboard diagnostic system has detected: Fuel Pump A Control Circuit High. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $50 - $500 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Fuel pump runs continuously with key off
- Reduced system performance
- Warning indicators on dashboard
Probable Causes (Ranked by Likelihood)
- Short to power in fuel pump A control circuit Very High
- Wiring damage or corrosion in the circuit High
- Poor electrical connection at module or component Moderate
- ECM or control module internal failure Low
Step-by-Step Diagnostic Procedure
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Use a scan tool to read data related to Fuel Pump A Control
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Inspect all related wiring, connectors, and grounds for damage, corrosion, or loose connections
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Measure circuit voltage, resistance, and continuity to identify the fault type
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Check for technical service bulletins related to this code for your specific vehicle
Frequently Asked Questions
Can P0629 prevent my car from starting?
Yes, if the fuel pump cannot operate due to this circuit fault, the engine will crank but not start because no fuel is being delivered to the fuel rail. You may hear the fuel pump priming sound absent when turning the key to ON.
Where is the fuel pump relay?
The fuel pump relay is typically located in the underhood fuse/relay box or in a relay center under the dashboard. Check your owner's manual for the exact location. It is often labeled 'FUEL PUMP' on the relay box cover.
Can I test the fuel pump relay?
Yes. Swap it with another identical relay in the fuse box (such as the horn or AC relay). If the fuel pump works with the swapped relay, the original relay is faulty. You can also test the relay with a multimeter and 12V power source.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0629 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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