ABS issue, Beeping and many dash lights

can you get the car ready and open the inverter coolant reservoir cap and see if the pump is working? If it's working properly, the fluid will have a boiling effect to it, when the pump is pumping fluid. If it's not working properly, then the fluid will not have much movement

 

To start, I'm sorry to hear you're having these problems and I understand 100% about wanting to keep the car going. At this time, the code reader you're using is not adequate and is likely directing you on a wild goose chase.

The P1121 code has nothing to do with the throttle, it is for the coolant control valve position sensor. The coolant control valve merely controls the flow direction of engine coolant into auxiliary systems. I've driven several Gen 2s with this code and none have had engine overheating problems, so I would say you are not in any immediate danger due to this code, but it should be repaired when reasonable. (assuming the code number itself is being read correctly).

P2238 is for the Air fuel ratio sensor, which is the upper sensor mounted in the exhaust header, not the O2 sensor mounted downstream at the catalytic converters.

It's very likely your reader is not capable of reading the specialty codes, so is showing nothing for your brake system, even though it's probably thrown codes. Your brake symptoms tend to lean toward an actuator issue. I've never seen a P1121 or 2238 cause secondary problems with brakes, but maybe it's possible. The P2238 also lists the ecm and integration relay as potential sources of the code, not only the sensor itself. Perhaps they have some overlap with the braking system.

 

The brake code was in post #2. ECB 41 is C1241, a complaint about the voltage reaching the brake system.

(ABS 42 and VSC 45 both only mean "hey, go look at the ECB code".)

 

Yes the 12v battery should be the first replacement before you do anything else. The battery could be the culprit giving out all these strange errors.

10.7v under a small load is pretty bad

 

C1241 is a particularly difficult to diagnose and fix. It seems even a lot of Toyota "master technicians" were not paying enough attention in class and can fail to come up with answers.

Although the 12 V battery is not a usual culprit with this code, be aware that sometimes the DC/DC converter is shut down and so the 12 V battery provides the power for the car until the 12 V battery voltage gets very low - somewhere below 10 V Therefore, you should check the 12 V battery (and for good measure the terminal connections at the battery and ground connection to the body that they are clean (free of corrosion) and tight) is not currently low. If it is lower than 12.3 V get it on a charger to fully charge it before doing any further diagnostics.

Voltages within or received at the ECU that set this code are much lower than 10 V – 8.9 V, 8.4 V, 5.3 V, 5 V, 4.9 V, or 4.7 V.

If you can get a scan done by someone with a good enough scanner that can get the DETAIL code (or sometimes called INF code) that goes along with the base C1241, that can help. Possible values for the INF code are 81, 82, 83, and 84. Getting the freeze frame data (FFD) would be useful too.

Possible areas that could be involved and can be checked are:

• ABS NO. 1 relay
• ABS NO. 2 relay
• Harness and connector - Skid control power supply circuit
• Brake control power supply assembly (This is the black box in the back under the floorboard next to the 12 V Battery.)
• Hybrid control system

If you want more information about troubleshooting this code, I've attached the repair manual troubleshooting procedure.

If you have any questions, please ask.

Good luck.

 

The battery could be damaged, but it is not necessarily a write-off. Charge and test first before condemning it.

The inverter getting too hot and shutting down the DC/DC converter is a definite possibility and in turn setting C1241.

Change the inverter coolant pump with a new OEM one and retest.

 

The drop from the initial small load at 11.9v to 10.7v is pretty significant (with nothing really on). Testing or not, it most likely won't be any good.

 

Sorry, I don't see where that was mentioned. But maybe yeah, if that is so.

[EDIT] Never mind JC, I just saw the images of the battery test. I missed that post altogether.

 

Nope, just make sure all air is bled out of the system. Judicious use of hose clamps can make sure very little air gets in and coolant is lost.

 

Generally, Toyota Hybrids develop an ABS module problem at this mileage. The ABS module uses an accumulator and a small DC motor to power the braking system/hybrid regen. They both degrade over time. The small DC motor has brushings that can be replaced but you'd have to have the right brushes which are hard to find. DIY this incorrectly and it'll cause electrical problems. The accumulator degrades and can't hold pressure.

Generally, I would specifically replace the broken part, but because the ABS module consist of several parts that are degrading, one should bite the bullet and just replace the entire module.

Scout ebay for some refurbished parts but it may be difficult to find parts with are in good condition and for a good price. The good news is that Prius parts are smaller and easier to work with compared to something on an SUV hybrid.

All that said, check the DTCs to find what the issue is first to see if it isn't something else.

 

She has and the codes don't implicate the ABS, for now.

 

She needs a better scantool to read all the trouble codes.

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