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2010 Chevrolet Camaro V6 LLT: P0023 Code Repeated with New Exhaust Cam Solenoids - OEM Works, Aftermarket Fails in Bank 2

Model: GM Fault Code: P0023 Posted: 2020-05-02 01:03

I recently replaced all four Variable Valve Timing (VVT) solenoids in my 2010 Chevrolet Camaro V6 LLT engine. After the replacement, the vehicle triggered Diagnostic Trouble Code (DTC) P0023 — indicating a fault with the Bank 2 exhaust camshaft solenoid. I tested three different aftermarket VVT solenoids in the Bank 2 exhaust cam position, and each time the P0023 code appeared. In contrast, when I installed the original factory OEM VVT solenoid back into the same location, the code cleared and remained gone. All other VVT solenoids (including those in different banks and intake positions) function properly. The only exception is Bank 2 exhaust cam position B. When I swapped the intake and exhaust VVTs between positions, the solenoid that was originally in the intake side began triggering a P0023 code when placed in the exhaust position — while the exhaust solenoid worked correctly in the intake spot. This indicates the issue is specific to this location and not a general failure of the solenoids or wiring. There are no open or short circuits detected, and resistance tests show all new solenoids read around 8 ohms (within expected range). The OEM solenoid reads between 8–10 ohms. I observed intermittent voltage at the plug — fluctuating between on/off states — which I initially thought was normal. However, after pushing the terminals inward to improve contact, a steady 10 volts was achieved when the key was ON and engine off. This suggests a combination of poor electrical connection and potential internal failure in the failed solenoid. I left the original OEM solenoid in place because it improved engine performance with advanced exhaust cam timing. After several stop/start cycles, the Check Engine Light did not illuminate. The system relies on feedback from the exhaust camshaft position sensor to verify that the VVT solenoid is responding correctly to commands from the Powertrain Control Module (PCM). Since this behavior only occurs in Bank 2 exhaust position B and not elsewhere, it points to a potential issue with either the solenoid design, connector fitment, or interaction between the PCM and cam sensor. I am seeking input from experienced GM technicians or owners who have encountered similar issues. This is not a general failure — it's a specific, location-based anomaly that should not occur if the ECU were simply misreading signals.

Related fault codes

P0023

Comments (6)

Anonymous 2020-05-02 09:20

Why did you replace all four solenoids? While some guides recommend replacing all when one is serviced, this situation seems isolated. I suspect it's a compatibility issue. Try using OEM AC Delco solenoids — they're widely available on Amazon and known for reliability. The PCM monitors the VVT solenoid operation via camshaft position sensor feedback. If the original factory part works but aftermarket ones don't, that strongly suggests the aftermarket component is faulty.

Anonymous 2020-05-02 11:48

The fact that all other new solenoids work in every position — including Bank 1 and intake cam positions — makes this issue highly specific. If it were a simple part failure, three different brands of aftermarket solenoids should show inconsistent performance across all locations. Since only the Bank 2 exhaust position B fails, and the same solenoid works when moved to intake side or swapped with an exhaust one, the problem is not general. This points to either a design flaw in that specific location or a mismatch between the PCM's expected signal and actual feedback from the camshaft sensor.

Anonymous 2020-05-02 12:33

With over 25 years of diagnostic experience, I'd say this is unlikely to be a wiring issue or a faulty PCM — because if those were present, they would affect multiple solenoids. The PCM sends pulse-width modulated (PWM) power to the VVT solenoid and also provides a constant ground. It relies on feedback from the exhaust camshaft position sensor to confirm proper operation. I recommend using an oscilloscope to monitor the control wire for PWM signals and comparing camshaft sensor readings between banks. A reliable scan tool with live data and output tests can help isolate whether the issue lies in the solenoid, wiring, or sensor response.

Anonymous 2020-05-02 13:58

I've verified all components again. The new VVT solenoids show ~8 ohms of resistance — within expected range. The OEM part reads between 8–10 ohms. A second coil tested at the store also showed 8 ohms. Voltage readings at the plug were erratic: around 10 volts when key was ON, but fluctuating. I initially thought this was normal for VVT operation. After pushing the terminals inward to improve contact, a steady 10 volts was achieved under key-on conditions. This suggests a combination of poor connector fit and internal coil failure in the failed solenoid. The car runs better with advanced exhaust cam timing now — I've kept the OEM unit installed.

Anonymous 2020-05-02 15:00

Resistance testing alone isn't sufficient to confirm functionality. A loaded-circuit test is more accurate, as the solenoid operates under actual load conditions when powered by the PCM's PWM signal. Poor electrical connections or internal component degradation can still result in normal resistance readings. Connector issues are also possible — especially with high-temperature environments and vibration exposure. Using a lab scope to capture real-time signals from both the VVT solenoid and camshaft position sensor would provide definitive insight into whether the PCM is receiving valid feedback.

Anonymous 2020-05-02 16:00

The issue has been resolved — after several stop/start cycles, the Check Engine Light did not come back on. The vehicle now runs smoothly with no P0023 or other related codes. However, I've noticed a new recurring DTC: P0430 (Catalyst System Efficiency Below Threshold Bank 2). This may be related to exhaust timing and catalytic converter performance, but it's a separate issue that will require further investigation.