Code Reader

[borgward]

Can a code reader be left connected while the car is being driven?

2013 Fiesta SE 30,000 miles reports engine needs maintenance but when I bring it in to have code read, there is no longer a code reported. Can the code reader be connected if I leave the engine running while the message is still being displayed?

There is something wrong. Usually happens when I turn on the cruise control. I get no throttle response until I push the throttle further in. Feels like when a carburetor circuit is not good on an old car. The car really decelerates when I let of the throttle. Idle is fine.

This happened a few months ago. Never could get a code read. The problem finally went away after a few days. It just came back. I think the throttle is by wire (electrical). I suspect the throttle unit is going out, or there is a bad connection between it and engine management. I am considering buying my own code reader if I can keep it connected until the problem occurs.

 

[Ethan1]

Whatever exactly does it say? Check engine? Wrench light? Maintenance required? You can plug a code reader in while the car is running, but that won't help if it's an errant code due to an electrical issue. If it's not a powertrain code or if it's a maintenance reminder, you will need a rather expensive scan tool to work on it.

 

[borgward]

I get both wrench light and maintenance required. Not maintenance reminder. As I reported, the throttle becomes wonky. How good a reader do I need? Who makes the good ones?

 

[Ethan1]

That sounds like textbook Ford electronic throttle body failure. It should set powertrain codes, so any code reader will help you confirm what's happening. You can get a bluetooth dongle for about $10 that lets you read the codes and see live data with a smartphone. For $15 or $20 you can get a simple reader on amazon or ebay that will display and erase powertrain codes. For $180 you can get an Autel Maxicheck Pro that will display codes, erase codes, and give you live data for all the car's major systems. The Autel could also probably display your codes after the engine is turned off because it supports history codes.

You could also swing into your local auto parts store the next time it happens and be sure to leave the engine running.

 

[Omahaug]

Is your code reader just a code reader or is it a scanner/scantool (and I'm not talking something like a Verus either). Mine offers live data and graphing even though it's just a glorified OBD2 reader, mine is designed to be used while the car is on so you can see live data for things like O2 sensor waveforms.

https://www.harborfreight.com/can-obd-ii-scan-tool-with-abs-60794.html

Just make sure to have it unplugged or off when the car is off so you don't drain battery.

 

[borgward]

I do not have a code reader.

 

[Wolf359]

Because it's a Ford, you can just use Forscan for free. No need to spend lots of money on more sophisticated scanners. Just a basic OBDII ELM327 will work, the recommended one is the BAFX one on Amazon which is usually around $20 but there are ones out there for under $10 if you're on a budget, not all of them are good though.

 

[eljefino]

Wrench and Maintenance lights are specifically not emissions related problems. If you're losing engine power that seems like it should affect emissions.

A cheap generic OBD scanner will only read emissions codes.

After the toyota accelleration fiasco I assumed all drive-by-wire systems had redundant systems. Eg two potentiometers on the gas pedal and a comparison circuit to make sure they're both the same. I'm baffled how the car doesn't know the actual throttle body isn't responding swiftly, or at all, to the gas pedal.

But if there aren't any emissions codes, a cheap code reader won't help. Even the dealers will sometimes triage incoming complaints to their lower tier oil change techs, who, if they can't find a code, will send you on your way.

Get them to drive it, acknowledge it, diagnose it, and fix it. Still under warranty?

 

[SHOZ]

Any scanner worth the electrons should be able to read throttle and accelerator positions in real time as a generic data PIDs. They should also be able to read all Pxxxx codes too.

The Torque app for my Hyundai has a plugin that goes deeper into Hyundais ECU and gets a lot more data like oil temps Absolute Load. And you can add gauges to the available data to make your own dash board.

When going this deep into the data it is well worth the money to buy a premium ELM327 adapter. OBDLink MX has Ford,GM,Chrysler added support.

For just display and code clearing the UltraGauge is nice and can be left connected. The cheap OBD ELM327s will drain the battery if left in too.

 

[Ethan1]

Originally Posted By: eljefino
Wrench and Maintenance lights are specifically not emissions related problems.


Sorry, no.

 

[borgward]

Not getting any Wrench, Engine light, or "Maintenance" message now. Car is running fine. I watched several YouTubes about the throttle mechanism. There is a plastic part on the side that contains the throttle position sensor. I saw that moisture gets in them causing corrosion. I think that's my problem.

We had 15" of rain here from Harvey. The ground is just drying out. I had been parking in the shade in a moist area. I am now parking on the drive in full sun light. Works for now, but is not the best solution.

Looks like OEM replacement part is $600. Maybe I can seal the sensor unit better after it is dried out (don't want to trap moisture in there)

I see refurbished units for $50 to $200. I am wondering where those guys are getting the totally unavailable sensors from. Maybe they are just pawning off used units as refurbished.

 

[SHOZ]

WD40 in copious amounts works great at ridding moisture for electronics and connectors.

 

[javacontour]

Originally Posted By: SHOZ
WD40 in copious amounts works great at ridding moisture for electronics and connectors.


Yep, the WD in WD-40 is short for Water Displacement. The story is this was formula 40 they tested and found it worked well.

 

[borgward]

I used to use LPS. It's what was recommended on M16's in Viet Nam. It used to be pretty available. They had several products. It was like WD40 on steroids. I sprayed it on a stock cam shaft I was replacing. Put it on a shelf and 15 years later it still had no rust. Was good for displacing moisture. Don't know if it has been bought out and degraded.

https://www.amazon.com/LPS-01916-Penetra...penetrating+oil

http://www.ebay.com/itm/LPS-57316-Penetrating-Oil-Syn-11oz-Aerosol-/222481497261?epid=1241112594&hash=item33ccee3cad:g:rTQAAOSwuspY9~mB

 

[borgward]

Have not found throttle position sensor for the Fiesta. Funny, as they are available for other Fords. I plan to remove the sensor, check for moisture and resulting corrosion. I found LPS 1 to displace moisture and deal with any corrosion.

LPS 1 http://www.lpslabs.com/product-details/560 Meets MIL-C-23411A

I plan to wrap electrical tape around the intersection of the plastic sensor and the metal throttle body to prevent any more moisture from getting into the unit.

Will any calibration or other operation need to be done once the sensor is re installed?

 

[SHOZ]

If it is an Electric Throttle Body the TPS is part of it and not separate. There usually is some sort of calibration you can do to them. Usually it's just turning the key on and doing nothing then shutting it off.

There should be an Absolute Throttle Position PID too. That's the one I look at.

 

[Anduril]

In my limited experience, a $13 Bluetooth adapter and the Car Gauge Pro app allowed me to read an ABS code stored in my Cavalier. Torque wouldn't do that. As for leaving the adapter connected, I probably had it connected to the car 24/7 for a month when I was trying to get it ready to pass emissions, no battery issues.

Since you can see O2 waveforms, other various sensor outputs, and MPG in real time, they're meant to be used while driving.

 

[SHOZ]

https://www.scantool.net/ has some adapters that work very fast and can be left in as they only draw a couple milliamps when on stand by. They are not the cheap kind though at around $50-$70. The MX is special with US Domestic bug three interaction.

And you can get plug in apps for Torque that are specific to certain manufacturers. The have EX in the name.

 

[borgward]

It is a separate plastic piece connected to the metal throttle body by clips. Many other Fords have a removable throttle position sensor. Many of them can be replaced by new ones. Did you mean that the TPS on the Fiesta is not removable, or a replacement is not available?

 

[SHOZ]

If it is separate then it should be available. The ETCs I have seen are all one unit.