FTC Reader Disclosure: When you purchase or register through links on our site, we may earn an affiliate commission at no extra cost to you. Read our Editorial & Advertising Policy.
P0172BMWBMW 5 Series HubAll BMW P0172Medium Severity

P0172 on BMW 5 Series: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0172 (System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix) specifically on the BMW 5 Series (2020–2026, 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV).

2020–2026
5 SeriesSedan
Sensor Voltage Ref
0.1V – 5.0V Ref
5 Series SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0172 On Another BMW Model:

1. Symptoms of P0172 on BMW 5 Series

When the Engine Control Module (ECM/PCM) on your BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV) logs fault code P0172, drivers commonly observe:

Check Engine Light on on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Strong unburnt fuel odor from exhaust on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Black carbon soot around exhaust tip on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Rough idle and engine bogging under throttle on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
Noticeable drop in MPG on BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV)
BMW 5 Series OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower kick panel near hood release lever. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on BMW 5 Series

Historical warranty claims and technical repair bulletins for BMW 5 Series point to the following failure distribution:

55%
Faulty or leaking fuel injector (BMW OEM Part)
25%
Contaminated Mass Air Flow (MAF) sensor (BMW OEM Part)
12%
Stuck closed EVAP canister purge valve (BMW OEM Part)
8%
Excessive fuel pressure regulator failure (BMW OEM Part)

3. Step-by-Step DIY Repair Guide for BMW 5 Series

01
Clean MAF Sensor and Throttle Body

Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on the BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

02
Check Short Term & Long Term Fuel Trims

Use live OBD-II scanner data; negative trims beyond -10% indicate the ECU is cutting fuel. on the BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

03
Inspect Fuel Injector Leak-Down

Perform a fuel pressure leak-down test to identify injectors leaking raw gasoline into cylinders while parked. on the BMW 5 Series equipped with 2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV.

Other Common Fault Codes on BMW 5 Series

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the BMW 5 Series:

4. BMW 5 Series P0172 FAQs

What causes code P0172 to trigger on a BMW 5 Series?

On the BMW 5 Series (2.0L Turbo (B48) / 3.0L Turbo I6 (B58) / 4.4L Twin-Turbo V8 (N63) / i5 EV), P0172 is most frequently caused by Faulty or leaking fuel injector or Contaminated Mass Air Flow (MAF) sensor.

Where is the OBD-II port located on my BMW 5 Series?

On the BMW 5 Series, the 16-pin DLC diagnostic connector is located Driver lower kick panel near hood release lever. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my BMW 5 Series with code P0172?

Driveable short distances, but unburnt fuel can damage catalytic converters. Given that P0172 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.