Turbocharger Engine Boost Condition - DTC Decoded: P1251

Toyota MR2

Code Description

Turbocharger Engine Boost Condition – Limit Exceeded 


Check Engine Light Illuminates on Dash and Code is Stored in ECM Bank


Turbo Solenoid Valve

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What The Tech Says

More times than not, the problem that throws this code is with the turbo solenoid valve. Mounted on the driver’s side of the engine near the top, it is a small cylinder-shaped plastic unit. This valve also has two vacuum hoses and an electrical connector. This valve operates the wastegate for the turbo and when faulty, it will cause the turbo to over or undercharge. Replacement of this valve is almost always a remedy for this problem. Please note that you should always replace parts such as these with genuine Toyota parts to restore proper function.

NOTE: Toyota doesn’t have too many models from the 1990s and 2000s that use a turbo, but that’s going to change beginning in 2015.