What Is The ‘Driver Motor A Control Module’…??? Code:POA1D

When you're searching for a trouble code, it helps to know the second character can only be a digit 0, 1, 2, or 3; it can't ever be a letter O, so when you search for P0A0D you probably get more/better results.

One of the computers in the car is called the HV control ECU (that's Toyota's name for it). If Toyota had assigned a trouble code of their own (in the P1 "manufacturer defined" code range), they could have called it "problem with the HV control ECU" and the naming would be perfectly clear.

But there was already a code assigned by SAE in the P0 range, for codes that should be standardized across different kinds of cars, so Toyota used the existing code that means generically a problem with some hybrid powertrain control module (module A, if the car has more than one). So you just have to know that the generic SAE-assigned fortune cookie for P0A1D happens to mean the HV control ECU if the car is a Gen 2 Prius.

That's the two-edged sword of standard codes: the good news is they're standard, so you don't have as many different manufacturer-defined codes to try to learn and deal with; the bad news is they're so generic that you still have to kind of translate them back to what they mean in the specific car you're looking at. That's what the repair manual is good for.

In the case of a Gen 2 Prius, the P0A1D code covers a whole bunch of possible issues with the HV control ECU, 57 different ones if I'm counting right. They are distinguished by the three-digit "INF code" that goes with the main code, and that some scan tools (like Toyota Techstream) will show.

So for a code like this one, it is very, very helpful to get a scan that shows the INF code. Otherwise there are just too many things the main code might mean.

Once you have the INF code, the repair manual has troubleshooting and repair steps to follow from there.

Toyota Service Information and Where To Find It | PriusChat

 

Welcome to PriusChat!!

DTC P0A1D has 50+ possible sub codes (AKA detailed code or INFs), you may need Techstream (dealership technician software that anyone can operate) or an appropriate OBD2 scanner that can report these toyota hybrid sub codes.

Knowing a possible INF (sub code or detailed code) for a particular DTC may save time and money when diagnosing.

P0a1d - with INF 134.pdf
P0a1d - with INF 139.pdf
P0a1d - with INF 140.pdf
P0a1d - with INF 141.pdf
P0a1d - with INF 142.pdf
P0a1d - with INF 143.pdf
P0a1d - with INF 144.pdf
P0a1d - with INF 148.pdf
P0a1d - with INF 150.pdf
P0a1d - with INF 159.pdf
P0a1d - with INF 163.pdf
P0a1d - with INF 165.pdf
P0a1d - with INF 166.pdf
P0a1d - with INF 177.pdf
P0a1d - with INF 180.pdf
P0a1d - with INF 187.pdf
P0a1d - with INF 188.pdf
P0a1d - with INF 390.pdf
P0a1d - with INF 393.pdf
P0a1d - with INF 568.pdf
P0a1d - with INF 615.pdf

FYI : you're being moderated until you've posted 5 times