Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSMAZDA20086 S SPORT, 4D HATCHBACK, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 543 (ON-BOARD DIAGNOSTIC (ABS/TCS))DTC U2021 [ABS/TCS]NOTES

2008 Mazda 6 s Sport, 4D Hatchback, Standard

DTC U2021 [Abs/TCS]: Notes

2008 Mazda 6 s Sport, 4D Hatchback, StandardSECTION Notes

WARNING: This page is about a different car, the 2007 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

To warm up the engine completely, idle the engine and wait for more than 5 minutes.

DTC U2021 [ABS/TCS] DETECTION CONDITION AND POSSIBLE CAUSES

DTC U2021	Engine coolant temperature
DETECTION CONDITION	After engine is warmed up, engine coolant temperature is 0 °C {32 °F} or less, and TCS operation is inhibited by PCM.
POSSIBLE CAUSE	System is normal. When engine coolant temperature rises, TCS operation is executed by PCM.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.