P2689 – BMW DTC

BMW DTC P2689 – Fuel Supply Heater Control Circuit High

DTC P2689 meaning on BMW

DTC P2689 on a BMW indicates a fault in the fuel supply heater control circuit, specifically a high voltage condition. The fuel supply heater is responsible for warming the fuel in cold weather conditions to improve combustion efficiency. When this code is triggered, it means that the Engine Control Module (ECM) has detected a voltage signal higher than the specified range in the fuel supply heater control circuit.

BMW DTC P2689 symptoms

Symptoms of DTC P2689 on a BMW may include:

• Check Engine Light (CEL) illuminated
• Reduced engine performance
• Possible hard starting in cold weather
• Decreased fuel efficiency

BMW DTC P2689 causes

The common causes of DTC P2689 on a BMW include:

• Faulty fuel supply heater
• Short circuit or open circuit in the fuel supply heater control circuit
• Corrosion or poor connections in the wiring related to the fuel supply heater
• Defective Engine Control Module (ECM)

BMW DTC P2689 seriousness

While DTC P2689 may not cause immediate drivability issues, it is important to address this fault promptly to prevent potential long-term damage to the fuel supply system and ensure optimal engine performance.

How to diagnose DTC P2689 on BMW

To diagnose DTC P2689 on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault code and freeze frame data.
2. Inspect the fuel supply heater and its wiring for any visible damage or corrosion.
3. Check the resistance of the fuel supply heater to ensure it is within specifications.
4. Test the voltage in the fuel supply heater control circuit to identify any anomalies.
5. Inspect the ECM and related connectors for signs of damage or poor connections.

How to fix DTC P2689 on BMW

To fix DTC P2689 on a BMW, consider the following steps:

1. Replace the faulty fuel supply heater if it is found to be defective.
2. Repair any short circuits or open circuits in the fuel supply heater control circuit.
3. Clean or repair any corroded or loose connections in the wiring related to the fuel supply heater.
4. If the ECM is determined to be faulty, replace it with a new unit.

How to erase DTC P2689 on BMW

To erase DTC P2689 on a BMW, you can use a diagnostic scanner to clear the fault code from the ECM’s memory. After performing the necessary repairs and confirming that the issue has been resolved, you can reset the ECM by clearing the code to turn off the Check Engine Light.

Recommended tools & DTC Scanners for BMW

Best Diagnostic App for modern BMWs: BimmerLink

Recommended Bluetooth adapter for Bimmerlink: OBDLink CX

Cable adapter for Bimmerlink: Enet Cable USB Type C

For older BMWs we recommend: Autel AutoLink AL319 (2024 version)

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

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