New member with a check engine light problem

[JerryB]

Hi all.
I have 2 Toyotas: A 1995 Tacoma with about 192,000 miles and a 2000 Echo with about 114,000 miles. My wife and I love them both! The problem is with the truck. About 2 weeks ago the check engine light came on. There does not seem to be any difference in performance, idling speed, engine roughness. Don't know about gas mileage as it is only driven around town a few days a week. Tried to retrieve codes with a jumper wire but the light remained steady. Tried a code reader and it said "no response". Tried removing the fuse but the light stayed on. Have not tried removing the battery cable yet as I don't think it will do any good. Has anybody come across this problem before? Anybody have any ideas what is wrong?

 

[tbplus10]

Normally if it isnt a hard fault they either reset themselves when the ignition is turned on/off or if the truck is driven app. a hundred miles, if it's a hard fault it must be reset by disconnecting the battery.
Your truck has OBD and you cant use a jumper wire to retrieve codes, you need to use an OBD reader. Most auto parts stores (Auto Zone, O'Reilleys, etc) will read the codes for you right in the parking lot for free.
First Gen Tacoma's are popular for throwing a hard code on the MAF sensor, if yours throw this code it's an easy fix, I normally start by disconnecting the battery so any codes can clear from the ECM.
Then remove the intake air supply tube containing the sensor from between the airbox and the throttle body, theres an electrical connector at the sensor and clamps at either end of the tube.
Using CRC "Sensor Safe" cleaner spray the sensor inside the tube liberally, never use a brush or rag on the sensor, even though it doesnt look delicate it is and can easily be damaged, hold one end of the tube down so everything drains out.
While the sensor/tube dry take this time to use some cleaner on a rag and wipe out the airbox behind the filter, using a nylon brush (I prefer an old toothbrush) and sensor cleaner, clean the throttle body and air flow plate.
Put everything back together.
The ECM should've had enough time to clear itself of any codes and reset while the battery was disconnected (normally takes about 3-4 minutes).
When starting the truck it wont want to fire up right away, dont hit the gas pedal let it turn over and start without an extra shot of fuel, again this may take a little longer than normal but is a part of letting the ECM reset properly. After starting the engine may stumble a little and take a moment to clear up to a normal idle, again dont hit the the gas pedal, allow the engine to idle for about 10 minutes for the ECM to stabilize and relearn running parameters.
Hopefully this cleared up your code, if not and you still have a MAF code you may need to replace the MAF Sensor.

 

[JerryB]

Check engine light problem fixed

Normally if it isnt a hard fault they either reset themselves when the ignition is turned on/off or if the truck is driven app. a hundred miles, if it's a hard fault it must be reset by disconnecting the battery.
Your truck has OBD and you cant use a jumper wire to retrieve codes, you need to use an OBD reader. Most auto parts stores (Auto Zone, O'Reilleys, etc) will read the codes for you right in the parking lot for free.
First Gen Tacoma's are popular for throwing a hard code on the MAF sensor, if yours throw this code it's an easy fix, I normally start by disconnecting the battery so any codes can clear from the ECM.
Then remove the intake air supply tube containing the sensor from between the airbox and the throttle body, theres an electrical connector at the sensor and clamps at either end of the tube.
Using CRC "Sensor Safe" cleaner spray the sensor inside the tube liberally, never use a brush or rag on the sensor, even though it doesnt look delicate it is and can easily be damaged, hold one end of the tube down so everything drains out.
While the sensor/tube dry take this time to use some cleaner on a rag and wipe out the airbox behind the filter, using a nylon brush (I prefer an old toothbrush) and sensor cleaner, clean the throttle body and air flow plate.
Put everything back together.
The ECM should've had enough time to clear itself of any codes and reset while the battery was disconnected (normally takes about 3-4 minutes).
When starting the truck it wont want to fire up right away, dont hit the gas pedal let it turn over and start without an extra shot of fuel, again this may take a little longer than normal but is a part of letting the ECM reset properly. After starting the engine may stumble a little and take a moment to clear up to a normal idle, again dont hit the the gas pedal, allow the engine to idle for about 10 minutes for the ECM to stabilize and relearn running parameters.
Hopefully this cleared up your code, if not and you still have a MAF code you may need to replace the MAF Sensor.

Sorry it has taken so long to reply but working 10 plus hours a day kinda wears me out. On Sunday I did what you suggested and it was the MAF sensor. After cleaning the sensor, the truck started right up with only a little stumble but smoothed out within 30 seconds.

Thanks for spot on advice. JerryB

 

[tbplus10]

Glad it worked out for you.

 

[TruckRider]

This is nice thread.. got some great info here