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Thanks for the opportunity to post her and join this forum.
My issue: 2013 Chevy Equinox 2.4L VVT with a P2090 code. The vehicle has 65k miles and runs perfectly fine with no noticeable issue and this is the only DTC. Oil always changed at prescribed schedule and always pure synthetic not a blend. No history of oil consumption. Cam Position solenoids were replaced a year or so when DTC’s identifying same first appeared. Since that time no issues or codes.
The current P2090 code states circuit low B cam sensor actuator.
On this vehicle there is only one bank naturally, the “B” in the code identifies the Exhaust cam sensor. There is a cam sensor AND there is an actuator or solenoid associated with the intake and exhaust cams. The code names actuator and sensor in the description but they are separate components required for VVT, nothing unusual here either. Upon seeing the code, I replaced the exhaust cam SENSOR with an AC Delco exact replacement as the likely suspect without any other diagnosis. So cleared code took a drive and same code returns. Also checked the exhaust cam solenoid by removing it to clean the screen and the electrical connections and confirmed solenoid electrical test for positive solenoid operation (using a 12v source), confirmed case to both pins to be open circuit and verified normal continuity of harness to ECM.
Therefore satisfied solenoid and electrical connections were normal. I did not scope the 12v PWM signal from the ECM that would drive the solenoid during normal engine running.
Further reading concerning P2090 suggest that this sensor signal is biased by the 5v rail and produces pulses timing that vary when as the exhaust camshaft timing triggers the sensor via the Hall effect. I did not probe the original sensor or the replacement sensor to confirm these pulses given the location, again a presumption that the harness integrity is well protected and in excellent condition “visually”,
Knowing that there is a history of valve chain stretching and with the tension guides, I concluded this was likely the the cause here. I took the car to my mechanic requested him to confirm this diagnosis before replacing the chain guides and cam sprockets. He confirmed but since he is still gathering parts and has not apparently begun the repair, I started thing about the code description and felt that possibly the presumptions I made were not founded and perhaps, my mechanic may have done the same thing. $1500.00 has a way of forcing more focused attention to presume NOTHING. At this point I have requested a hold on the repair to discuss exactly what steps the mechanic took before agreeing with my diagnostics.
The question to the forum is does anyone have any history with this engine to confirm that given the circuit low report associated with this code could this actually be an electrically based issue, most likely between the cam position sensor and ECM as the code screams it is?
Please help by offering your observations from any experience with this engine.
Thanks so very much!
Having dealt with a few of these, that code is specific to the small circuit that comprises the VVT solenoid, ECU, and two wires that control it. If it were a mechanical failure it would flag a VVT performance fault.
You said you didn't put a scope on PWM signal? I'd suggest scoping it and either commanding it on with a scanner or power braking it for a few seconds.
It appears that all the factory recommended testing for that code is centered around the solenoid, the circuit and the PCM.
I agree with donut, if this were a mechanical fault you would have performance or correlation codes.
Not a timing issue, IMO. Like others have said, this relates directly to the power side switched circuit that energizes the exhaust actuator solenoid.
I'd be looking for an open or high resistance in the low reference wire, or a short to ground in the control wire. Either will cause the PCM to detect a mismatch between the commanded state of that circuit, and the actual state. As in, it commanded 12V on the control wire, and saw 0V. Or, it commanded 0V and saw something else. Voltage tests at the exhaust VVT solenoid are needed.
Don't get me wrong - your LEA engine will need timing components sooner or later. :silly: They're just not causing your P2090.
