I have a ten year old non plug-in hybrid car (Toyota Camry) and had no problems over the last ten years driving it.

 

But now the hybrid battery seems to have given up and some functionality is disabled at software level (i.e. engine monitoring and cruise control!)

 

I went to a Toyota service garage and got the car inspected. They quoted 80,000 baht for a battery replacement.

 

I asked them to reset the electronics which they eventfully did. But they couldn't explain why engine monitoring and cruise control got disabled. I was told that they don't understand this and most people sell their car after six years...

 

After driving for another two month (after they had reset the electronics and put the battery online again) the same has happened again and the battery is now off-line, while engine monitoring and cruise control is disabled again.

 

Two major points that I want to clarify:

 

• What to expect, if I do go for a battery replacement?
• What to expect, if I get an "off-label" manipulation of the electronics and have the battery entirely remove, thereby in effect have a normal petrol car?

 

I am not looking for a general discussion if hybrids are good or bad. I would like to explore my options before I eventually buy a new car in the future.

Make sure it is not under warranty. Had a battery fail on a ten year old Prius. I had to pay several thousand baht, and Toyota covered the rest. After replacement, all is good again.

On a 10 year old car, I think I would just live without that functionality and not spend a penny on it.

If your Toyota hybrid has both engine monitoring (check engine light) and cruise control disabled, it usually indicates a problem with the car's computer system, likely due to a detected fault that could be anything from a loose gas cap to a more serious sensor malfunction, and as a safety precaution, the car disables features like cruise control until the issue is addressed; it's important to get your car scanned by a mechanic to identify the specific problem and get it fixed;. 

Key points about this situation:

Check Engine Light:

This light signifies that the car's engine control module has detected a potential issue and is storing diagnostic trouble codes (DTCs). 

Cruise Control Disablement:

Many modern cars, including Toyota hybrids, automatically disable cruise control when a check engine light is present as a safety measure. 

Possible reasons for the issue:

Sensor problems:

Faulty sensors like the oxygen sensor, mass airflow sensor, or coolant temperature sensor can trigger the check engine light and disable cruise control. 

Loose gas cap:

While seemingly minor, a loose gas cap can trigger a code and disable cruise control. 

Electrical issues:

Loose wires, faulty connections, or a failing alternator can disrupt the communication between the engine control module and other systems, including cruise control. 

Brake switch malfunction:

A faulty brake pedal switch can signal to the car that the brakes are applied even when they are not, preventing cruise control activation. 

Assuming they attached an OB2 scanner did they find any fault codes before resetting the ECU

7 hours ago, wimpy said:

Make sure it is not under warranty. Had a battery fail on a ten year old Prius. I had to pay several thousand baht, and Toyota covered the rest. After replacement, all is good again.

I guess you were still within the ten year warranty for the battery.

 

7 hours ago, vinny41 said:

If your Toyota hybrid has both engine monitoring (check engine light) and cruise control disabled, it usually indicates a problem with the car's computer system, likely due to a detected fault that could be anything from a loose gas cap to a more serious sensor malfunction, and as a safety precaution, the car disables features like cruise control until the issue is addressed; it's important to get your car scanned by a mechanic to identify the specific problem and get it fixed;. 

 

Thanks for the detailed explanations.

 

I guess, the errors might be just a false positive. Several lights come on (see pictures) when the Toyota technician reset the system there supposedly no errors. But I'll ask again this time to make sure nothing else is faulty.

 

 

 

 

Several error lights coming on at the same time usually indicates a faulty fuel cap, easy fix.

This guy is an great Toyota mechanic, he has many other videos on hybrids you can search for.

 

13 hours ago, Morakot said:

 

 

Thanks for the detailed explanations.

 

I guess, the errors might be just a false positive. Several lights come on (see pictures) when the Toyota technician reset the system there supposedly no errors. But I'll ask again this time to make sure nothing else is faulty.

 

 

 

 

This is typical of evaporative system errors. Remove the negative cable from the battery for about 15 minutes, this will clear the codes. And clean the fuel cap with a silicone spay, it may temporarily fix the problem. Replace the fuel cap with a genuine Toyota cap, the Chinese caps will last for only about a year.

I never owned any type of hybrid, but 1st you need to make sure (if the dealer is confused) that the symptoms are really related to old batteries (contact Toyota customer service, if such service is available in Thailand). If not, look for the problem else where. 

4 hours ago, novacova said:

This is typical of evaporative system errors. Remove the negative cable from the battery for about 15 minutes, this will clear the codes. And clean the fuel cap with a silicone spay, it may temporarily fix the problem. Replace the fuel cap with a genuine Toyota cap, the Chinese caps will last for only about a year.

How does a silicone spray 'clean' the cap? Why not a solvent spray such as a contact cleaner?

1 hour ago, PETERTHEEATER said:

How does a silicone spray 'clean' the cap? Why not a solvent spray such as a contact cleaner?

Yeah sure, fuel caps are generally not dirty enough for a solvent. Spray the inside of the cap with silicone spray which is designed to adhere to surfaces and will help create a seal that won’t contaminate the fuel tank. Use the solvent for something else incisively grimy and dirty like the brakes 

On 1/13/2025 at 9:11 PM, Morakot said:

I guess you were still within the ten year warranty for the battery.

It wasn't clear. The car was more than ten years. I think the original owner may have purchased some kind of extended warranty, because I had to pay a deductible of several thousand.