breet

1995 ES 300, automatic

Some back ground info: I was driving this car the other day and suddenly it stop moving properly----No matter how hard I hit the accelerration pedal, it would only move extramely slow at ~2 mile/hr. The engine was on during the whole time and switching it to lower gears do not help. I turned off the car and waited for a while and it was able to run as usual. The same thing happened the next day.

The mechanic found the OBD2 code P1605, which indicates the knock control CPU malfunction. He said there are many possiblities---it could be the ECU or the the knock sensor or even oil pump. Should I just try my luck and replace the ECU?

pauloil

if you're going to guess, start with the sensor. It is cheaper. Unless you have a donor ECU. if nothing else is bad, then I'd bet on the sensor in a car this old.

breet

But my car would still run if it is just the knock sensor.

Jlife22

I have this same code in my car now p1605. I wanted to know if you ever found out what the problem was? Thanks for any help!

Richardsr

Replace the sensor and lift the negative cable off your battery for about 15 minutes. If your ECU is having a problem, this may help “reset” it’s thinking.

Other possibilities included in Lexus P1605 codes are:
Possible causes Air Leak in Intake System, Faulty Mass Air Flow (MAF) sensor, Faulty Engine Coolant Temperature Sensor, Faulty Fuel Pump, Faulty Throttle Body Assembly, Faulty Engine Control Module (ECM).

https://www.autocodes.com/p1605_lexus.html