BMW OBD-II Error Code P1124

BMW OBD-II Major Air Flow / MAP

Model: OBD-II | Code: P1124

Applicable Systems
3 Series 5 Series X3 X5 7 Series

Symptoms

The ECM has detected a air flow and manifold pressure fault. The check engine light is illuminated. Vehicle may experience reduced performance, rough idle, or failed emissions test.

Possible Causes

  • Wiring open or shorted to ground
  • Connector corrosion or loose pin
  • Sensor internal failure

Troubleshooting Steps

  1. Step 1: Connect OBD-II scan tool and read all active DTCs
    DTC code and freeze frame data retrieved
  2. Step 2: Inspect wiring harness and connectors for damage or corrosion
    Wiring intact, connectors clean and seated
  3. Step 3: Test sensor or actuator resistance and signal output
    Component output within manufacturer specification
  4. Step 4: Check fuse for the circuit and replace if blown
    Fuse intact or replaced with correct rating
  5. Step 5: Clear DTC with scan tool and road test to verify repair
    No re-occurrence of DTC after test drive

How to Reset

To reset: Clear the DTC with an OBD-II scan tool after repairing the underlying issue. Drive the vehicle through a complete drive cycle to confirm the repair.

Frequently Asked Questions

  • Q: What does P1124 mean on a BMW?

    P1124 is a manufacturer-specific code indicating a air flow and manifold pressure issue. Refer to the BMW service manual for exact component identification.

  • Q: Can I drive with P1124 active?

    Short-term driving is possible, but the underlying issue should be diagnosed promptly to prevent catalytic converter or engine damage.

Related BMW Fault Codes

Source: SAE J2012 Manufacturer-Specific DTC, BMW Service Manual

Category: OBD-II