Car Wash Caused Hybrid System Warning

[rachaelseven]

Today my partner took the 2010 IV through the car wash for the first time - automatic car wash where you drive in, park, and the spray wands move around the car (no touch). When she got home, she told me (in somewhat of a panic) that 100 yards after she left the carwash, the dashboard lit up with a "Check Hybrid System" message and the yellow exclamation point. A single cycling of system power did not clear the message. Changing modes on the display would momentarily clear the big message block, but after allowing you to check the display for a few seconds, the big warning message came right back. Very scary!

I've read that in previous generations, 3 restarts are required to clear a warning message, as long as the problem had passed. However, rather than wait, I decided to plug in the Techstream and see what it had. The Hybrid Control ECU stored a code P0A2D with a description of "Drive Motor 'A' Temperature Sensor Circuit High". So I'm looking at the live data trying to find the 'Drive motor A temperature', but found no such thing. I don't know if "drive motor" meant MG1, MG2, ICE, or something else altogether. So I went to the freeze frame data... I love this Techstream... anyway, the freeze frame data also does not have a parameter by that name. Engine coolant temp was steady, as were both inverter temps. MG1 and MG2 temps also look normal as far as I can see. The aberrant temperature shows up as 249 next to the parameter "Information2" and further down next to "Detail Code 2". However, the frames immediately before and after have no value for those parameters at all. Perhaps a newer version of Techstream (I only have 4.12) would have additional detail, but that's what I've got. It's also quite likely that this was a just a glitch on the bus and that it doesn't actually correspond to any real sensor or condition.

After reading every possible piece of data and finding no ongoing fault, we took it on a test drive, with my partner monitoring the Techstream while I drove. All live parameters, including every temperature it shows (and there are a lot) were normal. So I reset the DTC, the message went away, and the car seems fine.

So the question is why did it occur? The battery had good charge and there was no obvious reason at the time. However, after thinking for a while my partner brought up the fact that I had been in the fuse box yesterday (pulling the radio fuse yesterday while trying to hack the NAV lockout). We checked the box and sure enough, I failed to completely latch the fuse box cover and it allowed some water into the fuse box. I thought it was only power distribution in there, but perhaps there is some access to the bus which allowed a momentary short. Even though the fault had no re-occured, we dried out the fuse box with a hair dryer to be on the safe side.

For now, I am going to assume that it was my improper latching of the fuse box cover that caused the fault, and unless it recurs, I will probably not waste my time going to the dealer with it. But I figured it was worth posting the thread anyway, in case anyone else has a similar issue and just so the information was out there. Latch that cover carefully!

[Bobsprius]

Originally Posted by rachaelseven

Today my partner took the 2010 IV through the car wash for the first time - automatic car wash where you drive in, park, and the spray wands move around the car (no touch). When she got home, she told me (in somewhat of a panic) that 100 yards after she left the carwash, the dashboard lit up with a "Check Hybrid System" message and the yellow exclamation point. A single cycling of system power did not clear the message. Changing modes on the display would momentarily clear the big message block, but after allowing you to check the display for a few seconds, the big warning message came right back. Very scary!

I've read that in previous generations, 3 restarts are required to clear a warning message, as long as the problem had passed. However, rather than wait, I decided to plug in the Techstream and see what it had. The Hybrid Control ECU stored a code P0A2D with a description of "Drive Motor 'A' Temperature Sensor Circuit High". So I'm looking at the live data trying to find the 'Drive motor A temperature', but found no such thing. I don't know if "drive motor" meant MG1, MG2, ICE, or something else altogether. So I went to the freeze frame data... I love this Techstream... anyway, the freeze frame data also does not have a parameter by that name. Engine coolant temp was steady, as were both inverter temps. MG1 and MG2 temps also look normal as far as I can see. The aberrant temperature shows up as 249 next to the parameter "Information2" and further down next to "Detail Code 2". However, the frames immediately before and after have no value for those parameters at all. Perhaps a newer version of Techstream (I only have 4.12) would have additional detail, but that's what I've got. It's also quite likely that this was a just a glitch on the bus and that it doesn't actually correspond to any real sensor or condition.

After reading every possible piece of data and finding no ongoing fault, we took it on a test drive, with my partner monitoring the Techstream while I drove. All live parameters, including every temperature it shows (and there are a lot) were normal. So I reset the DTC, the message went away, and the car seems fine.

So the question is why did it occur? The battery had good charge and there was no obvious reason at the time. However, after thinking for a while my partner brought up the fact that I had been in the fuse box yesterday (pulling the radio fuse yesterday while trying to hack the NAV lockout). We checked the box and sure enough, I failed to completely latch the fuse box cover and it allowed some water into the fuse box. I thought it was only power distribution in there, but perhaps there is some access to the bus which allowed a momentary short. Even though the fault had no re-occured, we dried out the fuse box with a hair dryer to be on the safe side.

For now, I am going to assume that it was my improper latching of the fuse box cover that caused the fault, and unless it recurs, I will probably not waste my time going to the dealer with it. But I figured it was worth posting the thread anyway, in case anyone else has a similar issue and just so the information was out there. Latch that cover carefully!

Thanks Rachel for the information. One thing that always makes me nervous if the first car wash (Automatic). I have heard the door locks and unlocks when the water touched the handle area. I found it interesting that when hand washing the car, fob in pocket, the door would lock and unlock with my wet sponge midway on the drivers door. So I guess it is quite sensitive.

Hope the first time I use an Automatic Wash I don't observe any error codes....as well.

Bob

[FreakinToddles]

Just to check, is that $500 cable you bought still the only option we are aware of to access techstream?

[rachaelseven]

Originally Posted by FreakinToddles

Just to check, is that $500 cable you bought still the only option we are aware of to access techstream?

It's the only tested and confirmed option. The $300 ISO/CAN version of the Mongoose cable (also made by Drew Tech and available on eBay) is a very high probability of success (Techstream recognizes it's drivers, at least), but without either testing one or pressing Drew for assurances, we won't know for sure.

[FreakinToddles]

Originally Posted by rachaelseven

It's the only tested and confirmed option. The $300 ISO/CAN version of the Mongoose cable (also made by Drew Tech and available on eBay) is a very high probability of success (Techstream recognizes it's drivers, at least), but without either testing one or pressing Drew for assurances, we won't know for sure.

Frustrating that they can charge $500 for a cable that costs $10 to manufacture...

[jay_man2]

I went through an automatic touchless today (3rd or 4th time in 12 weeks) with no issues, same as the other times. The only things I've touched under the hood are the dipstick and washer reservoir.

[rachaelseven]

Originally Posted by FreakinToddles

Frustrating that they can charge $500 for a cable that costs $10 to manufacture...

Actually, as cables go, this one's pretty fancy - board inside, LEDs, etc. But I think what really drives the price up is the programming of the drivers and getting it certified by Toyota (TIS lists it as a compatible device for J2534 programming). Well that and profit motive, of course.

[sciguy125]

Originally Posted by rachaelseven

Actually, as cables go, this one's pretty fancy - board inside, LEDs, etc. But I think what really drives the price up is the programming of the drivers and getting it certified by Toyota (TIS lists it as a compatible device for J2534 programming). Well that and profit motive, of course.

What magical device is this that you speak of?

[rachaelseven]

Mongoose MFC by Drew Tech. More details about my Techstream here:

Programming Ourselves?

[JasonPro]

I've been through a touchless wash several times now without an issue. I think you're on to something suspecting the fuse box getting wet.