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.
Diagnostic Procedures
2001 Chevrolet Cavalier LS, 2.4 TSECTION Diagnostic Procedures
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
- Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
- Turn ignition switch to RUN position, engine OFF. Command the HO2S 1 heater ON using a scan tool. Wait 15 seconds to allow the HO2S 1 heater current to stabilize. Observe the HO2S 1 heater current parameter using a scan tool. Is the HO2S 1 heater current parameter 0.217-1.56 amps? If yes, go to next step. If no, go to DTC P0135: HO2S HEATER PERFORMANCE - SENSOR 1 .
- Start the engine. Allow engine to reach operating temperature. Operate the engine at 2000 RPM for 30 seconds. Observe the HO2S 1 voltage parameter using a scan tool. Is the HO2S 1 voltage parameter varying above and below 300-600 mV? If yes, go to next step. If no, go to step 5.
- Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. 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. Did the DTC fail this ignition? If yes, go to next step. If no, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE - GASOLINE article.
- Turn ignition switch to OFF position. Disconnect the HO2S 1 harness connector. Turn ignition switch to RUN position, engine OFF. Observe the HO2S 1 voltage parameter using a scan tool. Is the HO2S 1 voltage parameter more than 800 mV? If yes, go to next step. If no, go to step 7.
CAUTION:
The sensor may be damaged if the circuit is shorted to a voltage source.
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.