P1790 – BMW DTC

BMW DTC P1790 – Internal Transmission Control Module Memory Check Sum/EPROM Error

DTC P1790 meaning on BMW

The Diagnostic Trouble Code (DTC) P1790 for BMW indicates an Internal Transmission Control Module Memory Check Sum/EPROM Error. This error occurs when the Transmission Control Module (TCM) detects an issue with the memory check sum or Electrically Programmable Read-Only Memory (EPROM) within the module.

BMW DTC P1790 symptoms

Symptoms of the BMW DTC P1790 may include:

• Transmission shifting issues
• Harsh or erratic shifting
• Transmission stuck in a particular gear
• Check Engine Light (CEL) illuminated on the dashboard

BMW DTC P1790 causes

Common causes of the BMW DTC P1790 include:

• Corrupted or faulty TCM memory
• Issues with the TCM EPROM
• Electrical interference or wiring problems

BMW DTC P1790 seriousness

The DTC P1790 for BMW should be addressed promptly as it can lead to drivability issues and potential damage to the transmission system if left unresolved. Ignoring this error code may result in further transmission problems and safety concerns.

How to diagnose DTC P1790 on BMW

To diagnose the DTC P1790 on a BMW, a mechanic would typically perform the following steps:

1. Use a diagnostic scanner to retrieve the fault codes stored in the TCM
2. Inspect the TCM wiring and connectors for any visible damage or corrosion
3. Check the TCM memory and EPROM for faults or corruption
4. Perform a thorough transmission system test to identify any related issues

How to fix DTC P1790 on BMW

Fixing the DTC P1790 on a BMW may involve the following steps:

1. Clear the fault codes using a diagnostic scanner and monitor the system for recurrence
2. Repair any damaged wiring or connectors in the TCM circuit
3. Reset the TCM memory or replace the TCM if necessary
4. Update the TCM software to the latest version to address any known issues

How to erase DTC P1790 on BMW

To erase the DTC P1790 on a BMW, follow these steps:

1. Use a diagnostic scanner to clear the fault codes stored in the TCM
2. Perform a test drive to ensure the issue has been resolved
3. If the fault code reappears, further diagnosis and repairs may be required

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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