A/C Error code b1498

Here are the possible issues causing B1498. If you are serious about resolving this issue I suggest you subscribe to the Toyota Europe techinfo site:
Toyota Service Information

You will also need Mini VCI and a digital multimeter.

1. Harness or connector between power management control ECU, compressor with motor assembly and body ground
2. Power management control ECU
3. Compressor with motor assembly
4. No. 2 engine wire (harness or connector between compressor with motor assembly and inverter with converter assembly)
5. Electric vehicle fuse
6. CAN communication system
7. Hybrid control system

 

I know this thread is old but were you ever able to resolve your issue? I had my engine replaced recently and I'm getting this code now.

 

Same here. You find a fix vintage?

Justin

 

I just had the engine replaced and have the same code. Did you guys figure out the issue?

 

The problem involves the communication of messages between the power management control ECU and the A/C inverter (which is inside the A/C compressor). The communication happens over a few wires you can find in the low-voltage (non-orange) electrical connector that plugs in on top of the compressor. That connector has ignition-switched power, ground, one wire for ECU-to-inverter data, one for inverter-to-ECU data, and a clock line. A little bit of electrical troubleshooting should pin down which circuit is messed up and how. You could start, of course, by just taking a good careful look at that connector.

These kinds of electrical gremlins are likely to be something one-off for each car, rather than turning out to have exactly the same cause as the last guy.

The code can also be set if the compressor is not receiving its high-voltage power (through the orange cable).

 

Hi ChapmanF. Thanks for the original reply. I'm not one who can handle the electrical trouble shooting so I ended up bringing it to the dealership for a diagnostic. They said there was a break in the #2 wiring harness & that it would cost about $1400 to replace. I did not have them do it. When I picked it up I had the "check hybrid system" message and orange triangle (amazingly this wasn't on until they did their diagnostic). They said that was because the bad wiring caused the fuse that powers the inverter to blow. Code is now P0AA6. Also said that they couldn't guarantee that even if they fixed it all that there wouldn't be some other problem with the compressor. Anyway, my question for you is whether what they're telling me makes sense. Is it likely that this break in the #2 wiring harness is the cause of the original B1498 code?

 

That no. 2 engine wire harness is just the orange one with two wires that runs from the inverter down to the compressor. It lists for $89.44 and is probably the easiest wire-harness replacement job on the planet (as long as you learn and follow the usual precautions for working near orange-colored things in the car). It straight-up plugs in at the compressor end, and bolts down at the inverter end, and has one support bracket that bolts to something.

You should have an inch-pound torque wrench for the inverter-end connections and get those right.

There is a fuse in the inverter that protects just that cable and the compressor, so it's possible a break in that wire harness could have blown that fuse. And the repair manual section for B1498 does say "The DTC is also detected if high-voltage power supplied from the inverter with converter assembly to the compressor control circuit is shut off."

Toyota Service Information and Where To Find It | PriusChat

P0AA6 (note that's a zero, not a letter O) indicates a failure of the high-voltage insulation somewhere. If they can give you the "INF" subcode that went with it, that would be more information. This picture is for a Gen 2:



One significant change happened for Gen 3: the "A/C inverter" is now part of the compressor itself, so the orange cable we're talking about would be reported in the blue 614 area in a Gen 3, and the whole green 611 area is inside the compressor itself. In a Gen 2, the orange cable is part of the 611 area.

I don't know how they get to $1400 for replacing a ninety-dollar cable with a plug and five bolts, but it sounds like a price you can probably beat DIY. Then even if it turned out there was still some compressor problem, you wouldn't feel as bad.

 

Thanks, ChapmanF. Very helpful!

 

Hi @ChapmanF. I'd like to ask you a follow-up on this. It's been a while, so recap: when my engine was replaced something happened that messed up my a/c (unless I'm to believe that it coincidentally happened to go out at the same time that the engine was replaced). Code was b1498. Still blows air but not cold. Guys who replaced it said the problem was the high voltage cable. Bought a used one but my regular mechanic said that wasn't the problem. Took it to Toyota and they said the problem was wire harness #2 (wanted a fortune to replace it) but couldn't be sure that there wasn't more wrong with the compressor once that was fixed. Took it to another place that replaced that wire harness for a reasonable price but AC is still blowing air that's not cold. I'm trying to figure out if the solution is that I need to replace the entire compressor or if there is another likely explanation. My mechanic will replace the compressor & charge the A/C for $400 if I buy a reconditioned one for a few hundred bucks (all in about $650). I would do this if I could be sure that it would fix the problem. Are the scenarios where I would have the compressor replaced and still not have the A/C work with this code? Thanks for any insight that you have.

 

I'm sorry, everyone, I really dropped the ball on this. I have had two people reach out to me asking how I resolved this and thought I added a reply.


In my case, I had to replace the AC compressor to fix it.