Signe
Full Access Member
My check engine light’s been on for a good year. A month after it came on, I took my KJ to Auto Zone for a quick check. I don’t recall the error code but I think it had something to do with a relay for the AC. Since the AC was working fine, I blew it off. A couple months later I drove by another parts store and had them check it out as well. They told me the same thing.
10 months later I make a 1,200 mile trip pulling a trailer. My KJ ran strong and the AC worked just fine the whole trip. The check engine light was still on. A couple weeks later the AC stopped blowing cold air for a couple minutes and I remember thinking it probably had something to do with that relay. The AC blew nothing but cold air for the next month and then, for a couple minutes one day, it stopped blowing cold air again. It started blowing cold air again after a couple minutes.
A month later I took my KJ to the dealership. The error code they gave me was P0601. The service guy types the code into his computer and tells me I need a new ECU. This really turned me off because he never asked me how long the check engine light had been on nor if my KJ was giving me trouble. Not only that, he immediately called the parts department and said he’s gonna give me an estimate. He’s yet to ask me a single question and he’s yet to take my KJ out for a spin. I politely told him not to bother with the estimate.
I drove down the street to another Auto Zone and they give me the same error code: P0601. The printout he gives me says the probable causes are:
1) A shorted input sensor
2) A shorted electrical circuit
3) Failed ECM
He asks me how my KJ is running and I tell him it’s running as strong as ever (it’s got almost 93,000 miles.) He then tells me it’s unlikely the ECU is bad because, at the least, my KJ wouldn’t be running well. I never told him about the AC because, as I type this, it’s been blowing nothing but cold air.
P.S. The same printout I got from Auto Zone says the definition of P0601 is "ECM internal fault." The explanation reads "ECM unable to communicate on the SPI line."
10 months later I make a 1,200 mile trip pulling a trailer. My KJ ran strong and the AC worked just fine the whole trip. The check engine light was still on. A couple weeks later the AC stopped blowing cold air for a couple minutes and I remember thinking it probably had something to do with that relay. The AC blew nothing but cold air for the next month and then, for a couple minutes one day, it stopped blowing cold air again. It started blowing cold air again after a couple minutes.
A month later I took my KJ to the dealership. The error code they gave me was P0601. The service guy types the code into his computer and tells me I need a new ECU. This really turned me off because he never asked me how long the check engine light had been on nor if my KJ was giving me trouble. Not only that, he immediately called the parts department and said he’s gonna give me an estimate. He’s yet to ask me a single question and he’s yet to take my KJ out for a spin. I politely told him not to bother with the estimate.
I drove down the street to another Auto Zone and they give me the same error code: P0601. The printout he gives me says the probable causes are:
1) A shorted input sensor
2) A shorted electrical circuit
3) Failed ECM
He asks me how my KJ is running and I tell him it’s running as strong as ever (it’s got almost 93,000 miles.) He then tells me it’s unlikely the ECU is bad because, at the least, my KJ wouldn’t be running well. I never told him about the AC because, as I type this, it’s been blowing nothing but cold air.
P.S. The same printout I got from Auto Zone says the definition of P0601 is "ECM internal fault." The explanation reads "ECM unable to communicate on the SPI line."