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.
2001 Saturn SW2 AutomaticFACTORY OEM SERVICE PROCEDURE
On-Board Diagnostics: Monitors
- Comprehensive Component Monitor
Monitors PCM systems for opens, shorts, grounds and out-of-range sensors. Also monitors rationality of sensors. Rationality is whether the sensors value is consistent with the operating conditions of the other sensors. - Misfire Monitor
Monitors engine misfire using crankshaft sensor to determine location and severity of misfire. A catalyst damaging misfire will flash the MIL, and a non-catalyst damaging misfire is a normal type "B" code. - Fuel Trim Monitor
Monitors short and long term fuel trim for being at maximum lean or rich limit. - Oxygen Sensor Monitor
Monitors all oxygen sensors for maximum voltage level, minimum voltage level and lean rich/rich lean switching rate. - Oxygen Sensor Heater Monitor
Monitors oxygen sensor heater by watching sensor's time to activity after a cold start. - Catalyst Monitor
Monitors catalyst efficiency by comparing activity rate of precatalyst oxygen sensor and postcatalyst oxygen sensor. - EVAP Monitor
Monitors EVAP system for large leaks, small leaks and purge flow. - Secondary Air Monitor
Monitors secondary air operation.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no 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.