The General Motors (GM) drive cycle is a standardized procedure used to test a vehicle’s emissions system and ensure it meets OBDII (On-Board Diagnostics II) requirements. Successfully completing this cycle allows the vehicle’s computer to perform diagnostics on various systems and potentially clear any stored trouble codes. While specifically designed for GM vehicles, it’s often applicable to other makes, like Jeep, as well. This cycle can typically be completed in under fifteen minutes.
Steps to Perform the GM Drive Cycle for OBDII Reads Inc.
Following these steps closely will maximize the chance of a complete diagnostic run and accurate OBDII reads:
1. Cold Start
The engine must be cold, meaning the coolant temperature is below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature. Avoid turning the ignition on before the cold start, as this might prevent the heated oxygen sensor diagnostic from running. This initial step is critical for accurate Obdii Reads Inc. data related to emissions.
2. Idle
Let the engine idle for two and a half minutes with the air conditioner and rear defroster on. Applying additional electrical loads helps test components more thoroughly. This phase checks the O2 heater, passive air system, purge “no flow,” misfire detection, and fuel trim if closed loop is achieved. Proper idling ensures accurate OBDII reads inc. information for these systems.
3. Acceleration
Turn off all accessories and accelerate at half throttle until reaching 88 km/h (55 mph). This tests the misfire, fuel trim, and purge flow diagnostics, providing valuable data for OBDII reads inc.
4. Hold Steady Speed
Maintain a constant speed of 88 km/h (55 mph) for three minutes. This tests the O2 response, air intrusion, EGR (Exhaust Gas Recirculation), purge, misfire, and fuel trim systems. These readings are crucial for comprehensive OBDII reads inc. analysis.
5. Deceleration
Release the accelerator and allow the vehicle to coast down to 32 km/h (20 mph) without braking or shifting gears. This step focuses on the EGR, purge, and fuel trim diagnostics. Accurate deceleration data ensures precise OBDII reads inc. results.
6. Acceleration (Second)
Accelerate at 3/4 throttle to 88-96 km/h (55-60 mph), mirroring the diagnostics performed in step 3. This second acceleration phase further verifies data for OBDII reads inc.
7. Hold Steady Speed (Second)
Maintain a constant speed of 88 km/h (55 mph) for five minutes. This extended period allows the catalyst monitor diagnostics to run, in addition to the tests from step 4. A marginal catalyst or disconnected battery might require up to five complete driving cycles for a conclusive diagnosis. This stage is vital for accurate OBDII reads inc. related to the catalytic converter.
8. Deceleration (Second)
Repeat the deceleration process from step 5, allowing the vehicle to coast down to 32 km/h (20 mph) without braking or shifting. This final deceleration provides further validation for OBDII reads inc.
Successfully completing the GM drive cycle ensures comprehensive diagnostic data is available for accurate OBDII reads inc., enabling effective troubleshooting and repair of emissions-related issues.
