Should I Clear Fault Codes To Diagnose Potential Problem?

I've owned my Taco since I bought it brand new in 11/04 and have logged over 146K miles on it. I've been fortunate with this truck and have not had any mechanical or electronic issues (other than the AM radio randomly changing stations on its own which somehow stopped a while back). The check engine light just went on for the first time in 16 years. Whatever triggered the light doesn't seem to affect the operation of the vehicle. My thought is that the ECU has probably logged in a lot of faults over the 16 years and some of those problems no longer exist. Should I clear all of the fault codes to start with a fresh slate and then operate the vehicle to determine whether there are any current problems that need to be addressed?

 

They periodically dismiss codes on their own if the problem resolves, if you're seeing the light stay on it's time to scan the ecu and see what the code is. You can begin diagnosis now.

 

if you havnt had a check engine light on, and now do, it will only show current faults/pending codes. Not all previous codes. Have the code read n go from there

 

Best bet is to note down all the codes and their status (pending/historical/current), clear them and see what reoccurs. At that age/mileage, and with no other noticeable symptoms likely an 02/AF sensor or evap code.

 

Not all fault codes will set the CEL.

 

You need to get a code scanner, read the code, and note exactly what it is.

At that point, I'd be tempted to erase the code and see if it returns.

While you can do this with a very inexpensive code scanner (maybe $15 to $20 on Amazon)....If you have a tablet or smart phone and want some more flexibility, I recommend the bluedriver OBD2 Port scanner. I got one delivered ($100) this week and it is very cool to be able to not only scan for check engine codes, but all other codes as well...also do real time graphing of selected engine parameters....and most importantly view actual sensor voltage levels with the associated specs that (I HOPE) will end up saving me a lot of money over the years by narrowing down exactly what is causing a CEL rather than guessing which one of several different causes should I start with.

$100 BlueDriver Bluetooth Pro OBDII Scan Tool for iPhone & Android

https://www.amazon.com/dp/B00652G4TS?ref=ppx_yo2_dt_b_product_details

Phil

 

FYI you can get codes read for free at any autozone/orileys etc. A standard OBD code reader is cheap, and you can get bluetooth OBD scanners for under 10 bucks.