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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSCHEVROLET2008CHEVY EXPRESS G2500, VAN CARGO, 6.6 6REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1366 (ENGINE CONTROLS AND FUEL - 4.4L - DTC P0010 TO DTC P0158)DTC P0101 OR P1101CIRCUIT/SYSTEM TESTING
2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6
Circuit/System Testing
2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Visually and physically inspect the by-pass valve and cable for any of the following conditions:
- A binding or sticking when opening or closing
- An incorrectly adjusted cable
- If any of the above conditions are found, refer to Supercharger Cleaning and Inspection .
- Verify the integrity of the entire supercharger air induction system by inspecting for the following conditions:
- A restricted or collapsed air intake duct
- A misaligned or damaged air intake duct
- A dirty or deteriorating air filter element
- Any objects blocking the air inlet probe of the MAF/IAT sensor
- Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor
- Any water intrusion in the induction system
- Any unmetered air downstream of the MAF/IAT sensor
- An intake manifold leak
- Any snow or ice build up at the air cleaner or MAF/IAT sensor
- A SCIAP sensor vacuum hose that is missing or damaged
- A MAP sensor vacuum hose that is missing or damaged
- Ignition OFF, disconnect the harness connector at the MAF sensor.
- Ignition OFF for 90 seconds, test for less than 5 ohms between the ground circuit terminal B and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance.
- Ignition ON, test for 4.8-5.2 volts between the MAF sensor signal circuit terminal A and ground.
- If less than the specified range, test the MAF sensor signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
- If greater than the specified range, test the MAF sensor signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
- Ignition ON, verify that a test lamp illuminates between the MAF sensor ignition 1 voltage circuit terminal C and ground.
- If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
- Ignition OFF, connect the read lead of J 38522 to the signal circuit terminal A at the MAF/IAT sensor harness connector. Connect the battery voltage supply to B+, and ground the black lead.
- Set the J 38522 signal to 5 volts, the Frequency to 5K, and the Duty Cycle to Normal.
- Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz.
- If the MAF Sensor parameter is not within the specified range, replace the ECM.
- If all other circuits test normal, test or replace the MAF Sensor.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.