Check Engine Light / Code: P0606

[Bbellz]

A few days ago my check engine light illuminated. I scanned the code and got P0606 01/02 and P0606 P 2/2. I looked up the code and it stems from a bad ECM. However, other things like LED lights, faulty O2 sensors and AF sensor could also throw the code as the bad ECM is supposedly related to electrical checks the ECM does.

I will consistently get the P0606 code on a cold start. However, if I clear the code and drive the vehicle the check engine light does NOT come back on until the following day when I cold start the vehicle. Recently I drove 150 miles / 3 hours after clearing the code and didn't get a check engine light until the following day after a cold start. So this issue seems to be related to the issue being cold vs. warmed up.

Thus far I've clean the battery terminals in the odd event that was the issue, but it wasn't. I read that LED lights can throw this code so I replaced my LED reverse lights with regular bulbs, but that didn't fix the issue.

I'm leaning towards it being a bad oxygen sensor, but not sure how to diagnosis which of the 4 it may be. The engine did sort of stumble on start up a couple days ago, but generally it runs smooth.

Any advice on how to proceed diagnosing this issue? If I need a scan tool that can log data please give me any recommendations you have.

Thanks,
Bill

 

[084RUNNAH]

Sounds like the ECM. Some sort of internal issue.

I would look at the sensors downstream Bank 1 Sensor 2 and bank 2 sensor 2. Unhook them, clean and reconnect them

Any changes to the vehicle?

 

[Bbellz]

Are you referring to the electrical connectors or the actual sensors? If the actual sensors what can I clean them with? Thanks!

 

[084RUNNAH]

Electrical connectors. Could be loose or dirt got in them as a guess. If it doesn’t help, a scanner would go a long way

 

[samsonx]

A few days ago my check engine light illuminated. I scanned the code and got P0606 01/02 and P0606 P 2/2. I looked up the code and it stems from a bad ECM. However, other things like LED lights, faulty O2 sensors and AF sensor could also throw the code as the bad ECM is supposedly related to electrical checks the ECM does.

I will consistently get the P0606 code on a cold start. However, if I clear the code and drive the vehicle the check engine light does NOT come back on until the following day when I cold start the vehicle. Recently I drove 150 miles / 3 hours after clearing the code and didn't get a check engine light until the following day after a cold start. So this issue seems to be related to the issue being cold vs. warmed up.

Thus far I've clean the battery terminals in the odd event that was the issue, but it wasn't. I read that LED lights can throw this code so I replaced my LED reverse lights with regular bulbs, but that didn't fix the issue.

I'm leaning towards it being a bad oxygen sensor, but not sure how to diagnosis which of the 4 it may be. The engine did sort of stumble on start up a couple days ago, but generally it runs smooth.

Any advice on how to proceed diagnosing this issue? If I need a scan tool that can log data please give me any recommendations you have.

Thanks,
Bill

Bill, did you figure this out? My 4runner also throws this code quite often, sometimes on cold start, but also sometimes while driving.

Thanks,
Sam

 

[Ph03n1x24]

Bill, did you figure this out? My 4runner also throws this code quite often, sometimes on cold start, but also sometimes while driving.

Thanks,
Sam

ECM/PCM power or ground connector?

Silly question: Have you checked the battery? I saw on another forum where a weak battery can cause this code to pop.