Locate under BM Options. Change this value from the default 16 down to 1 .
BMW INPA Error 159: Comprehensive Troubleshooting and Fix Guide
Bridges pins 7 and 8. This is required for older BMWs (roughly 1998 to March 2007, like the E46, E39, and early E60/E90).
The USB serial port settings in Windows default to a transmission delay that is too slow for BMW factory diagnostics.
By default, Windows sets USB serial ports to a latency of 16 milliseconds. INPA requires a latency of to maintain a stable connection with BMW modules. Plug your K+DCAN cable into your laptop's USB port. inpa error 159
Find the file named ediabas.ini . Right-click it and open it with . Use Ctrl + F to search for the term Buffer .
The following factors are the most frequent triggers for Error 159, ranging from hardware physical connection issues to software configuration conflicts. 1. Hardware Connection Issues
If you are still experiencing connectivity issues, let me know: What and year you are working on
: The most frequent culprit. Your COM port latency must be set to 1ms . Locate under BM Options
If the error persists, the setup is more complex.
Users often don't know where the break is occurring (Laptop → Cable? Cable → Car? Car → Module?). DIS - Fault 200 159 - Bimmerforums - The Ultimate BMW Forum
If you only get Error 159 on one specific module (e.g., Airbag or ABS) but can read the Engine ECU fine, that specific module may have blown a fuse or completely failed. Step-by-Step Troubleshooting Guide
The COM port assigned to your cable in Windows Device Manager does not match the INPA configuration files ( obd.ini ). This is required for older BMWs (roughly 1998
or "IFH-0009: No response from control unit."
If INPA continues to fail, test your diagnostic cable with other software:
: Ensure the cable's LED is active. If your car is pre-2007, check if you need a K+DCAN switch cable to bridge pins 7 and 8.
If you own an adjustable cable, slide the manual toggle switch to the opposite side and attempt re-entry. Step 4: Refresh Outdated SP-DATEN Binary Files
Follow these troubleshooting steps in order. Most users find that step one or step two resolves the issue completely. Step 1: Change the USB Latency Timer (Most Common Fix)
