U1138 – BMW DTC

BMW DTC U1138 – Message Monitoring Idle-Speed Control Valve DPR Overwrite Error (Bank 1)

DTC U1138 meaning on BMW

The Diagnostic Trouble Code (DTC) U1138 for BMW refers to the Message Monitoring Idle-Speed Control Valve DPR Overwrite Error on Bank 1. This error code indicates a problem with the idle-speed control valve, specifically related to the Data Processing Relay (DPR) on Bank 1 of the engine.

BMW DTC U1138 symptoms

Symptoms of the BMW DTC U1138 may include:

• Engine stalling at idle
• Rough idling
• Decreased engine performance
• Check Engine Light (CEL) illuminated on the dashboard

BMW DTC U1138 causes

Possible causes of the BMW DTC U1138 include:

• Faulty idle-speed control valve
• Wiring or connection issues related to the DPR on Bank 1
• Software or programming errors

BMW DTC U1138 seriousness

The DTC U1138 for BMW should be addressed promptly to prevent potential engine performance issues and further damage. Ignoring this error code may lead to drivability problems and increased fuel consumption.

How to diagnose DTC U1138 on BMW

To diagnose the DTC U1138 on a BMW, follow these steps:

1. Use a diagnostic scanner to retrieve the fault codes stored in the vehicle’s Engine Control Module (ECM).
2. Inspect the idle-speed control valve and its wiring for any visible damage or loose connections.
3. Perform a DPR test to check for proper functionality on Bank 1.
4. Check for any software updates or reprogramming needed for the ECM.

How to fix DTC U1138 on BMW

To fix the DTC U1138 on a BMW, consider the following:

1. Replace the faulty idle-speed control valve if necessary.
2. Repair any damaged wiring or connections related to the DPR on Bank 1.
3. Update the ECM software to the latest version.
4. Clear the fault codes and perform a test drive to ensure the issue is resolved.

How to erase DTC U1138 on BMW

To erase the DTC U1138 on a BMW, use a diagnostic scanner to clear the fault codes stored in the ECM memory. After clearing the codes, perform a test drive to verify that the issue has been resolved and the Check Engine Light is no longer illuminated.