Hello, these codes can be set if you are losing coolant due to a leak or possibly a head gasket issue. The first code (P261b) can sometimes be taken care of by properly bleeding the coolant system, so if you're low on coolant it can set both of these codes. So, the real issue to begin with is finding out where the coolant leak is. That is probably the overall cause of these codes. The P261b is the ECM detecting the coolant pump below 900 RPMs so the code trouble area is labelled as 1. Open or Short circuit in engine water pump assembly circuit. 2. Engine water pump assembly 3. ECM issue,
The p148f Problem Area is. 1. lack of engine coolant, 2. Engine coolant leak, 3. Engine water pump assembly.
And the code detection for that one (p148f) engine water pump assembly speed has been more than the target amount.
So, the first thing is to determine the coolant leak. Since you said you're actually missing coolant, that is your main concern. Doing a pressure test on the coolant system will help determine where the leak is. If the coolant is low, I can see how the pump can actually spin faster than it should since there's a lack of coolant/pressure to push.
If it's only been a month since you had the pump replaced, you should be able to bring it back to the place that replaced it and explain that it's losing coolant. They should have checked for a leak to begin with if you were getting these codes. Not just replaced the pump without checking the system completely. Especially on a system like this where the engine computer monitors the pump speed and circuit conditions. I will post the code definitions in just a minute.
https://www.2carpros.com/articles/radiator-pressure-test
https://www.2carpros.com/articles/coolant-leak-symptoms
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Jan 14, 2022 at 4:48 PM
