My 2007 Toyota Corolla suddenly lost acceleration (car remained running, but nothing happened when I hit the gas pedal). Check Engine light came on and battery light also came on. I pulled over, shut the car off, and restarted it. The Check Engine light came on again, but the car started fine, and I was able to drive home without any issue. Possible electrical or ECM issue? The ECM was replaced under warranty several years ago.
Your vehicle has a drive-by-wire throttle system.
Instead of having a throttle cable between the throttle pedal and the throttle body, your vehicle has a throttle pedal position sensor sensor that sends a signal to the computer, and the computer operates the electronic throttle body.
Some auto parts stores will pull trouble codes for free.
Find one that does, and see if the code is related to the electronic throttle system.
Tester’s idea is where to start. Another idea if that doesn’t pan out, since the battery light was on with the engine running – that should never happen if the battery and alternator are working correctly – have the alternator tested to make sure it is charging the battery properly. If the battery isn’t fully charged the low voltage can confuse the computer.
It looks like this may be an ECM issue:
The ECM was replaced once already (at 30,000 miles). The car has 117,000 miles on it now, so it’s well past the warranty coverage. Apparently, having the ECM fail more than once is not unusual for 2003-2008 models.
On the bright side, maybe replacing the ECM will magically fix the weird ongoing issue with the AC blower motor…
The link that you posted is for a recall, you stated that the ECM was replaced, wasn’t that the recall repair? Was the recall not completed?
Ten years of warranty has been added to the ECU and electronic throttle control related parts on your vehicle as a result of the Economic loss class action settlement, up to 150,000 miles.
ECM failure is speculation, what caused your engine to stall will need to be diagnosed.
No, the ECM has no control of the blower motor. The blower motor is a simple circuit that can be diagnosed with a test light.
The blower motor on my own Corolla hasn’t worked for years in the low speed. I just use it on the higher speeds instead. In my case the problem I’m guessing is the blower resistor needs to be replaced.
When your ECM was replaced before, was it b/c there was a drivability problem? Or was it done pro-actively, no problem wthe car, but b/c of a recall?
The ECM was replaced because of a known issue, but this was done prior to the actual recall (It might have been done in 2008 or 2009), and the issue was a bit different. A diagnostic code wouldn’t clear, and I’m pretty sure that it was the maintenance light that stayed on as a result rather than the check engine light. Anyway, I haven’t checked the part numbers yet, but I wouldn’t be surprised if the replacement ECM has the part number specified in the recall. I got all kinds of recall notices for the Takata airbag issue, but now I’m wondering if any of those might have been for the ECM.
No. The ECM was replaced in 2008 or 2009 for a known issue but before any recall. The issue was slightly different, too, as the problem then was that a diagnostic code wouldn’t clear resulting in the maintenance light (rather than the check engine light) staying on.
I was kidding about the AC blower. I’ve posted endlessly on that subject in another thread. It’s the bane of my car’s existence at this point.
Suggest to post all the diagnostic trouble codes from the computer’s memory maybe folks here will have some more ideas. ECM’s should only be replaced when there’s a proven reason it needs to be done. So hold off on the ECM replacement idea until the other stuff above has been ruled out.
I’m actually taking it to Toyota on Friday. It stopped responding to pressure on the gas pedal again this morning while driving, so it seems kind of urgent. Toyota will do the diagnostics for the same price as a BlueDriver would cost (I don’t currently have an OBD reader), anyway.
If it is the ECM, I know you can buy those for a lot less than Toyota will charge. However, don’t they need to be programmed before installation?
Programming may be required, but what needs to be done, if anything, is vehicle make/model/year/configuration specific. That’s why ECM’s shouldn’t be replaced on a whim.
Off the main topic, but I heard on the radio today Hyundai is introducing technology which will allow car owners to download needed ECM programming instructions to their car via their cell phones, no need to take it to a dealership. I’m not sure if that’s good news or not. If the manufactures can make software updating easy for them, they may decide to release their software without full the full test regime, thinking the customers can fix any problems later by downloading patches via their cell phones. This makes the car owner a B-test site for the manufacturer rather than a customer, sort of like some computer software companies treat their customers now.