P2634 Buick Code - Fuel Transfer Pump Relay Control Circuit High Voltage
Quick Answer
The Engine Control Module (ECM) enables the secondary fuel pump relay when the primary fuel tank is below approximately 50 liters (13.2 gallons) and will run until the primary tank is filled to approximately 70 liters (18.5 gallons) or until the secondary tank is empty. Common causes include Faulty Secondary Fuel Pump Relay, Secondary Fuel Pump Relay harness is open or shorted, Secondary Fuel Pump Relay circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P2634 Buick indicates Fuel Transfer Pump Relay Control Circuit High Voltage.
- Common causes
- Common causes include Faulty Secondary Fuel Pump Relay, Secondary Fuel Pump Relay harness is open or shorted, Secondary Fuel Pump Relay circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P2634 Buick Description
The control module monitors the voltage on the fuel transfer pump relay control circuit. If the control module detects an incorrect voltage on the fuel transfer pump relay control circuit, a fuel transfer pump relay control Diagnostic Trouble Code (DTC) sets.
What are the Possible Causes of the DTC P2634 Buick?
- Faulty Secondary Fuel Pump Relay
- Secondary Fuel Pump Relay harness is open or shorted
- Secondary Fuel Pump Relay circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P2634 Buick?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P2634 Buick code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P2634 Buick Code
1. What does the OBDII code P2634 mean on a Buick?
P2634 indicates a high voltage issue in the fuel transfer pump relay control circuit, which can affect the fuel delivery system's performance.
2. What are the common symptoms of code P2634 in a Buick?
Symptoms may include difficulty starting the engine, reduced fuel efficiency, stalling, or the check engine light being illuminated.
3. What causes the P2634 code to appear on a Buick?
Possible causes include a faulty fuel transfer pump relay, damaged wiring or connectors in the circuit, or a malfunctioning fuel pump control module.
4. Can I drive my Buick with the P2634 code active?
Driving with this code is not recommended as it could lead to engine performance issues or cause the vehicle to stall unexpectedly.
5. How do you diagnose the P2634 code on a Buick?
Diagnosis involves using a scan tool to confirm the code, inspecting the fuel transfer pump relay and circuit wiring, and testing the fuel pump control module.
6. How is the P2634 code repaired on a Buick?
Repairs may include replacing the fuel transfer pump relay, repairing damaged wiring or connectors, or replacing the fuel pump control module if it is faulty.
7. What tools are needed to fix the P2634 code on a Buick?
You may need a diagnostic scan tool, a multimeter for testing voltages, and basic hand tools for inspecting and replacing components.
8. How much does it cost to fix the P2634 code on a Buick?
Repair costs can vary but generally range from $100 to $500, depending on whether the issue is with the relay, wiring, or control module.
9. Can a weak battery cause the P2634 code on a Buick?
While unlikely, electrical issues like a weak or failing battery can sometimes exacerbate voltage-related codes. It's worth testing the battery and charging system.
10. Is the P2634 code specific to Buicks, or does it apply to other vehicles?
P2634 is a generic OBDII code, so it can appear on other makes and models, but repair steps may vary depending on the vehicle.
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