How to reset a check engine light w/out scan tool?

[Rockit]

Does anyone know if you can clear a code without a scan tool. I've heard 10 starts will clear it? I've also heard key on, step on gas pedal 10 times? have no idea.

2006 3.0 liter, just replaced Secondary Air Pump.

I got the code reading from a shop an hour North of me but don't want to drive back up to turn off the light.

Thanks for any help.

[NotAnyoneYouKnow]

Unhook the negative battery cable for a few minutes.(Even a few seconds should do.)

[Qsilver7]

Stomping on the accelerator pedal is for cars that are OBD I (built before 1996).

Disconnecting the battery cable WILL NOT reset a CEL/SES/MIL warning light on an OBD II car (from 1996-up). Because if the issue is still present during the "drive cycle test"...the light will re-illuminate.

If the OBD II system passes the FTP (federal test protocol) "drive cycle"...the warning light will reset itself (without a scanner/reader/etc).

{Explanation of OBD I & OBD II}



{FTP Drive Cycle Chart}
{top half of chart shows time/speed intervals required to engage the drive cycle test on lower half of chart}

[Rockit]

Originally Posted by Qsilver7

Stomping on the accelerator pedal is for cars that are OBD I (built before 1996).

Disconnecting the battery cable WILL NOT reset a CEL/SES/MIL warning light on an OBD II car (from 1996-up). Because if the issue is still present during the "drive cycle test"...the light will re-illuminate.

If the OBD II system passes the FTP (federal test protocol) "drive cycle"...the warning light will reset itself (without a scanner/reader/etc).

{Explanation of OBD I & OBD II}



{FTP Drive Cycle Chart}
{top half of chart shows time/speed intervals required to engage the drive cycle test on lower half of chart}

Thanks so MUCH "Q" any idea hw many starts it takes to clear now fixed?

[Qsilver7]

Originally Posted by Rockit

Thanks so MUCH "Q" any idea hw many starts it takes to clear now fixed?

It's not about "starts"...as mentioned above...the OBD II FTP (federal test protocol) has an established "drive cycle" where monitors are tested (see the chart in post above). Some of the monitors require two test because they monitor hot and cold situations...so following the outlined FTP drive cycle...may not clear all of the test monitors the first time if the monitor requires a "hot" and "cold" reading. It may occur in another drive cycle. Try to define a driving route/course that will allow you to accomplish the requirements for meeting the tests as outlined on the top half of the FTP drive cycle chart above.

OBD2 Readiness Monitors Explained

The purpose of readiness monitors is to self-test the car’s emission control systems. The monitors are also known as Emissions Monitors. Like the name indicates, they observe the performance of car’s emission related systems.

Cars may perform up to 11 system tests or routines. These tests are so called readiness monitors. The output of readiness monitors tell you whether the car’s computer has completed the tests successfully.

Readiness Monitor types

There are two different types of readiness monitors: continuous and non-continuous. Continuous monitors are different in design from the non-continuous ones. Continuous monitors are being constantly tested and evaluated while the engine is running. The non-continuous monitors need certain conditions to be met before a test can be completed.

The conditions necessary to run the non-continuous self-diagnostic tests vary. Some monitors require that the car follows a predefined drive cycle routine. Some require two drive cycles because of the need for a cool down and warm up periods between. Each emission monitor can have different requirements for the conditions.

Previously, the OBD2 standard (SAE J1979) categorized each defined monitor as either one. In the latest standard edition, this definite allocation is no longer present for all of them. Thus, OBD Auto Doctor doesn’t follow the categorization anymore either.

Continuous or Non-continuous Monitors

These monitors can be of either type. It’s up to the manufacturer to decide.

• Misfire
• Fuel System
• Comprehensive Component
• Non-Continuous Monitors

Non-continuous monitors are different for spark ignition cars (gasoline engines) and compression ignition cars (diesel engines).

• Spark ignition vehicles (Gas)

• Catalyst (CAT)
• Heated Catalyst
• Evaporative (EVAP) System
• Secondary Air System
• Oxygen (O2) Sensor
• Oxygen Sensor Heater
• EGR (Exhaust Gas Recirculation) and/or VVT System
• Compression ignition vehicles (Diesel)

• NMHC Catalyst
• NOx/SCR Aftertreatment
• Boost Pressure
• Exhaust Gas Sensor
• PM Filter
• EGR and/or VVT System

Monitoring cycles

Traditionally, the only monitor status was the status since the diagnostic trouble codes were cleared. This readiness monitor status is mandatory for all OBD2 compliant vehicles.

As the OBD2 has evolved, newer vehicles can now report emission monitor status also for the current driving cycle. These monitors start from the beginning every time when the monitoring cycle begins. Older cars might not support this feature.

Monitor status

Readiness monitor test result yields the monitor status. Each readiness monitor will have its own output status. The completion status can be:

Complete or ready meaning that the test has been completed. It means that the OBD-II system has checked this emissions control system and it has passed the test.

Incomplete or not ready meaning the test is not completed. It means that the OBD2 system has not been able to run this routine or it has failed.

Disabled meaning that the test has been disabled for the rest of this monitoring cycle. A monitor can be disabled when there is no easy way for the driver to operate the vehicle to allow the monitor to run. For example, the ambient air temperature might be too low or too high.

[AceEngineer]

Hey Rockit,

In this day and age you don't have a scan tool? Buy one of these:
https://www.ebay.com/itm/ELM327-HH-V...kAAOSwxa9azNzJ
It's less than $10 and it talks to an app on your phone. You can erase codes with it. I use a program called "Torque" available in the PlayStore for a couple of bucks. You will love it if you are any kind of gearhead. Am I not right guy's??

AceEngineer

[jdstrickland]

Go on eBay or Amazon and get an ELM-327 module. If it specifies that it works with Apple or Android, get the right one. Then go the app store for your phone and get an OBD II app. The module plugs into the OBD II Data Port in your car and talks to the app on your phone. You can pull codes and clear the computer from your phone or tablet. You can also keep tabs on the Readiness Monitors so you know if they are coming to ready.

The apps come in Free Versions, and Fee Based Versions. You can play with a few free versions before buying the fee-based version. The fee versions allow you to build log files of things like fuel trims if that sort of thing excites you.

[XGrrl]

In my experience, it takes about 3-4 hours of driving to clear most codes. I recently bought a neglected 2005 X5 3.0 with every warning light lit and I've cleared them all on their own. I have an ELM-327 with the Torque app so I could clear them, but I get an odd satisfaction seeing them go out all by themselves.