P3075 on Buick: How to Diagnose & Fix
Engine Coolant Pump Low Current Performance
1 Buick model · 1 documented issue · $600-$1,500 repair
P3075 on Buick by model: symptoms, diagnosis and fix
On the 1.3L engine, the check-engine light can come on with code P3075 (engine coolant flow too low). GM bulletin 21-NA-257 says this may be caused by low coolant or air trapped in the cooling system; GM TechLink also describes P3075 and/or P0128 set by failure of the engine coolant flow control valve. Applies to: 2020-2022 Buick Encore GX with the 1.3L L3T engine (bulletin 21-NA-257); GM TechLink lists 2020-2025 Encore GX with the 1.3L for the control valve failure. The 1.2L LIH is not listed.
Common Symptoms
- Engine overheats after 20-25 minutes of driving
- Temperature gauge reads erratically or swings high then normal
- Engine overheat / idle engine warning message
- Heater blows cold or only warm at idle
- Coolant loss with no obvious external puddle
- Check engine light
How to Fix
Under bulletin 21-NA-257, a technician pressure-tests the cooling system, repairs any leak, fills and bleeds it per GM procedure and confirms the P3075 test passes; if the car returns a second time with P3075, the coolant pump assembly is replaced. GM TechLink adds a borescope check of the coolant control valve while cycling it with the scan tool: if it cycles smoothly the engine control module is reprogrammed, and if not the valve is replaced and the module reflashed. Normal warranty rules apply; this is not a recall or a promise of free repair.
Sources for this issue (3)
P3075 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P3075 mean on a Buick?
P3075 stands for "Engine Coolant Pump Low Current Performance." General Motors powertrain code. On engines with an electrically driven or electrically assisted coolant pump, the ECM monitors the current the pump draws as a proxy for how much coolant it is actually moving. P3075 sets when engine coolant pump current falls outside its calibrated range for more than about three seconds — the pump is drawing too little current, which means it is not moving the expected volume of coolant. GM describes the resulting condition as engine coolant flow too low; the pump is often working correctly and the real problem is that it has nothing solid to pump, because the system has lost coolant or has air in it. On Buick it is documented across 1 model: Encore GX.
What are the most common causes of P3075?
The most common causes of P3075 are: Low coolant level from an external leak, Air trapped in the cooling system after a coolant service or a leak, letting the pump cavitate, Leaking plastic coolant control valve / integrated water pump assembly or its housing — a known failure point on GM 1.2L/1.3L/2.7L engines, Leaking radiator hose connection, thermostat housing or radiator, Electrical fault in the coolant pump circuit — wiring, connector or failed pump motor, Stuck coolant control valve or restricted coolant passage, Faulty ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P3075 on a Buick?
Published repair estimates on Buick range from $600 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.