What does Buick P0171 mean?

Buick code P0171: System Lean Bank 1. It relates to the powertrain on Buick vehicles.

Can P0171 be turned off in the ECU?

DTC removal is possible for off-road/motorsport use after the underlying fault or hardware change (e.g. DPF/EGR removal). Safety-critical codes should be fixed, not suppressed.

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Buick P0171

System Lean Bank 1

What P0171 means on a Buick

On Buick vehicles, P0171 is logged when the ECU detects a fault in the powertrain: “System Lean Bank 1”. P0171 is a generic SAE code — see the universal P0171 page too.

Common causes & symptoms

Typical triggers for a powertrain code like P0171 include faulty or ageing sensors, wiring/connector faults, a clogged or removed component, or a value drifting outside the ECU's expected window. Symptoms range from a check-engine light only, to limp mode, rough running, higher consumption or failed emissions tests.

P0171 and ECU tuning

When a Buick has had hardware changed for off-road/motorsport use (for example a removed DPF or EGR), the related monitor must be disabled in the ECU map or the code re-appears. Softechpro Solutions performs DPF/EGR/AdBlue/DTC off and recalculates the checksum, so codes like P0171 stay cleared after the flash. Genuine faults should always be repaired, not just hidden.

Related Buick codes

P1031 P1032 P1105 P1106

Need to clear P0171 after a delete?

Softechpro Solutions does DPF/EGR/AdBlue/DTC off + checksum for 260+ ECU families — from €98.99/mo.

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