Two months ago my Chevrolet Aveo 2007 had intermittent interior and exterior light flickering problem that was especially noticeable while idling or driving at low speeds. Also, one morning the car had to be jumpstarted due to low battery. I also noticed strange ~1 Volt drop over battery terminal and the clamp connecting to it (there is remote possibility I may have misused multimeter, but I doubt about it). So, instead of assuming alternator or battery issues, I decided first to clean and e-grease connections to the battery terminals and, surprisingly, the issue went away.
However, after two months my car simply stalled after driving first 20 meters. This time there was no interior or exterior light flickering. There were no status lights in the dashboard (e.g. the red battery light indicating starter issues). So, I checked the codes with OBD2 reader and they were:
- P0340: Camshaft Position Sensor Circuit Malfunction
- P2106: Throttle Actuator Control System Forced Limited Power
- P2110: Throttle Actuator Control System Forced Limited RPM
- P2101: Throttle Actuator Control Motor Circuit Range/Performance
When I try to start the car I see that starter engages and the belt spins as expected, but the car still won't start.
Also the battery voltage drop this time between + and - at the time when starter spins is 12.5V to 10.8V (without Nekteck jumpstarter assist) and 12.03V to 11V (with Nekteck jump start assist). This is the first time I am using portable battery jump start assist so I haven't verified if it actually works.
Now I am trying to make sense out of all of this:
- Is the issue this time with something else like Camshaft Position Sensor? Is there an easy way to know if it is good or bad?
- Is the issues with starter/alternator again showing up and possibly causing the P0340 code due to weak starter? How to know if alternator is good or bad?
Here is picture of my camshaft sensor with its connector unplugged. I suppose there should be 5V square wave with oscilloscope (or 2.5v with multimeter) between orange and black wire? Is the easiest way to probe for that voltage simply by splicing the cables or shall I intercept somewhere else?
Below is how I wired up everything. At the time of cranking the voltage between yellow and black wire jumped from 1.2V to 1.4V. Note, that I have a cheap multimeter and I am not sure if it is able to properly measure voltage for non-sinusodial wave functions.
So this how the sensor output looks like on oscilloscope. Obviously, don't look like nice square waves:
Update4 I changed the camshaft position sensor and the P0340 code disappeared, but the car still does not crank up. The voltage drop at the time of cranking now is from 12.0V to 10.8V.