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 MANUALSCHEVROLET1997CHEVY EXPRESS G3500, VAN CARGO, 6.5 FREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 71 (ENGINE CONTROLS - TESTS W/CODES - 5.0L)DIAGNOSTIC TROUBLE CODESDTC P0154 - HO2S INSUFFICIENT ACTIVITY BANK 2, SENSOR 1DIAGNOSTIC PROCEDURES
1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 F
Diagnostic Procedures
1997 Chevrolet Chevy Express G3500, Van Cargo, 6.5 FSECTION Diagnostic Procedures
WARNING: This page is about a different car, the 1998 GMC Savana, 1998 Chevrolet Chevy Van, and 1998 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
- Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
- Connect scan tool. Warm engine to normal operating temperature. Run engine at greater than 1200 RPM for 2 minutes. If scan tool indicates closed loop, go to step 5). If scan tool does not indicate closed loop, go to next step.
- Turn ignition off. Disconnect HO2S harness connector. Connect jumper wires between ground, and HO2S ground and HO2S signal circuits of HO2S connector (VCM side). Turn ignition on, engine off. Using scan tool, monitor HO2S voltage. If HO2S voltage is less than .2 volt (200 mV), go to next step. If HO2S voltage is not less than .2 volt (200 mV), go to step 6).
- Turn ignition off. Remove jumper wire. Check voltage between battery voltage and HO2S low circuit. If voltage reading is about 12 volts, go to step 7). If voltage reading is not about 12 volts, go to step 9).
- DTC is intermittent. If no additional DTCs are set, see DIAGNOSTIC AIDS. If any additional DTCs are set, go to applicable DTC test.
- Check for open in HO2S signal circuit. If circuit is open, go to step 11). If circuit is okay, go to step 8).
- Check for faulty/poor connection at HO2S. If connection is faulty, go to step 11). If connection is okay, go to step 10).
- Check for poor connection at VCM connector. If connection is faulty, go to step 11). If connection is okay, go to step 12).
- Repair open in HO2S ground circuit. After repairs, go to step 13).
- Replace HO2S. After replacing sensor, go to step 13).
- Repair circuit as necessary. After repairs, go to step 13).
- Replace VCM. Program replacement VCM using required equipment. After replacing VCM, go to next step.
- Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter this DTC. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step 2).
- Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
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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.