P140B – BMW DTC

BMW DTC P140B – Secondary Air Injection System Insufficient Total Flow (Bank 1 and Bank 2) and Insufficient Flow (Bank 1)

DTC P140B meaning on BMW

The DTC P140B code on a BMW indicates a fault in the Secondary Air Injection System, specifically pointing to insufficient total flow in both Bank 1 and Bank 2 of the engine.

BMW DTC P140B symptoms

Symptoms of the BMW DTC P140B code may include:

• Check Engine Light (CEL) illuminated on the dashboard
• Reduced engine performance or power
• Increased emissions
• Engine misfires or rough idling

BMW DTC P140B causes

Common causes of the BMW DTC P140B code include:

• Faulty Secondary Air Injection Pump
• Blocked or restricted Secondary Air Injection System passages
• Malfunctioning Secondary Air Injection System valves
• Wiring or electrical issues in the system

BMW DTC P140B seriousness

The DTC P140B code should not be ignored as it can lead to increased emissions, reduced engine performance, and potential damage to other components if left unresolved. It is recommended to address this issue promptly to ensure proper engine operation and emissions compliance.

How to diagnose DTC P140B on BMW

To diagnose the DTC P140B on a BMW, a mechanic may perform the following steps:

1. Use a diagnostic scanner to retrieve the fault codes and freeze frame data
2. Inspect the Secondary Air Injection System components for any visible damage or blockages
3. Test the Secondary Air Injection Pump and valves for proper operation
4. Check the wiring and connectors for any signs of damage or corrosion

How to fix DTC P140B on BMW

To fix the DTC P140B on a BMW, the following steps may be taken:

1. Replace the faulty Secondary Air Injection Pump or valves if necessary
2. Clean out any blockages or restrictions in the system passages
3. Repair any damaged wiring or connectors in the Secondary Air Injection System
4. Clear the fault codes and reset the Check Engine Light using a diagnostic scanner

How to erase DTC P140B on BMW

To erase the DTC P140B code on a BMW, follow these steps:

1. Use a diagnostic scanner to clear the fault codes from the vehicle’s computer
2. Ensure that the underlying issue causing the fault code has been addressed and resolved
3. Start the engine and check for any recurrence of the DTC P140B code

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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