Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET2012CHEVY EXPRESS G2500, VAN PASSENGER, 4.8L ENG VIN AREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1251 (ENGINE CONTROL SYSTEM & FUEL - HYBRID (HP2) 6.0L (LFA) - DTC P0231 TO DTC P0690)DTC P0341CIRCUIT/SYSTEM VERIFICATION
2012 Chevrolet Chevy Express G2500, Van Passenger, 4.8L Eng VIN A
Circuit/System Verification
2012 Chevrolet Chevy Express G2500, Van Passenger, 4.8L Eng VIN ASECTION Circuit/System Verification
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
- Ignition OFF, inspect the engine wiring harness carrying the CMP sensor circuits for the following conditions:
- Close routing of aftermarket electrical equipment
- Close to solenoids, motors, and relays
- If any of these are determined to be a possible source of electrical interference, correct any wire harness routing or component placement conditions.
- Start the engine. Using the Live Plot function on the scan tool, select the CMP sensor parameter. Change the minimum spec to 400, and the maximum spec to 4,000 RPM. Select the CKP sensor parameter. Change the minimum spec to 600, and the maximum spec to 3,300 RPM.
- Observe the scan tool.
- Quickly accelerate and release the accelerator pedal several times. Do not accelerate past 3,200 RPM. The graphed lines on the Live Plot display should track together across the screen.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.