Just recently, I have been getting the P0128 code which suggests the thermostat or ECT sensor is bad. There is a TSB out for this problem but I recently had my PCM updated and the dealer said this update would have solved the problem if the PCM was the cause. The temperature gauge in my car never moves a millimeter once it is warm so I do not think the thermostat is the problem. I have read that the P0128 code is based on a calculation that includes input from the MAF and IAT sensors which seem to be the more likely suspects. Does anyone have any advise before I start replacing parts?
I have read that this P0128 code does not let the Mazda3 get out of open-loop (start-up) mode. I am not sure if this statement was accurate but the author was confident that this trouble code would impact engine performance. My car has not behaved any differently since the CEL first came on about six weeks ago due to the P0128 code. My problems are intermittent, only happen when accelerating, go away for hours (sometimes day), but always come back. When my car is experiencing the problems the gas mileage is poor (21 vs 28 mpg) and there is excessive carbon build-up on the muffler tip. I am not sure if my problems are related to the P0128 code but I sure hope so.
have the same problem?
Monday, August 24th, 2009 AT 4:47 PM