C1046 – BMW DTC

BMW DTC C1046 – Brake System Vacuum Pump Fuse Defective

DTC C1046 meaning on BMW

DTC C1046 on a BMW indicates a fault related to the brake system vacuum pump fuse being defective. The vacuum pump fuse is crucial for the proper functioning of the brake system, as it provides the necessary vacuum pressure for brake booster operation.

BMW DTC C1046 symptoms

Symptoms of DTC C1046 on a BMW may include:

  • Brake warning light illuminated on the dashboard
  • Loss of power assistance in the brakes
  • Hard brake pedal feel

BMW DTC C1046 causes

The common causes of DTC C1046 on a BMW are:

  • Blown vacuum pump fuse
  • Short circuit in the wiring related to the vacuum pump fuse
  • Faulty vacuum pump

BMW DTC C1046 seriousness

The seriousness of DTC C1046 on a BMW should not be underestimated, as it directly affects the operation of the brake system. Driving with a faulty brake system can compromise safety and lead to potential accidents. It is crucial to address this issue promptly.

How to diagnose DTC C1046 on BMW

To diagnose DTC C1046 on a BMW, follow these steps:

  1. Use a diagnostic scanner to retrieve the fault codes from the vehicle’s computer
  2. Inspect the vacuum pump fuse for any signs of damage or being blown
  3. Check the wiring connected to the vacuum pump fuse for any visible issues
  4. Test the vacuum pump for proper operation

How to fix DTC C1046 on BMW

To fix DTC C1046 on a BMW, you can:

  1. Replace the blown vacuum pump fuse with a new one of the correct amperage
  2. Repair any wiring issues related to the vacuum pump fuse
  3. If the vacuum pump is faulty, replace it with a new one

How to erase DTC C1046 on BMW

To erase DTC C1046 on a BMW after fixing the issue, you can:

  1. Use a diagnostic scanner to clear the fault codes from the vehicle’s computer
  2. Ensure that the repair has been successful by checking for any recurring fault codes

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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