Ford electronic throttle.....Informational.

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5,765
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Fort Worth, Texas
Had a 2007 Ford Five Hundred with a 3.0L Duratech come in last week. *Symptoms.....Random Stall at idle & Engine cut-out with throttle input over 25%. *DTC's...... P060A-Internal Control Module Monitoring Processor Performance P2105-Throttle Actuator Control (TAC) System - Forced Engine Shutdown P2107-Throttle Actuator Control (TAC) Module Processor U0300-Internal Control Module Software Incompatibility PCM & Throttle Body have been replaced by a Ford Dealer the week before. QE1 pinpoint tests for P060A, P2105, U0300...... Are any DTCs present other than the following: P0600, P060A, P060B, P060C, P061B, P061C, P061D, P061F, P062C, P1674, P2104, P2105, P2106, P2110, or U0300? YES - DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Diagnostic Trouble Code (DTC) Charts and Descriptions. DV pinpoint tests for P2107....... DV24 DTC P2107: CHECK FOR OTHER SELF-TEST DTCS Note: DTC P2107 may set when a failure mode effects management (FMEM) action is taken. If the FMEM DTC P2110 is present with other DTCs, diagnose the other DTCs before diagnosing the DTC P2110. Are any DTCs present other than P2107 and P2110? YES - DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO to Section 4, Diagnostic Trouble Code (DTC) Charts and Descriptions See: Computers and Control Systems > Diagnostic Trouble Code Tests and Associated Procedures > Diagnostic Trouble Code (DTC) Charts and Descriptions. As you can see Ford Pinpoint Tests leave A LOT to the imagination in certain situations! Both PT's say to disregard the code & diagnose the next DTC. Reading further into the DV24 PT has you check the wiring between the Throttle Body & PCM, Seems logical as the PCM & TB have been replaced. Checked the wiring very thoroughly, Load tested the TB Motor control circuits with a Halogen Bulb & they can definitely carry more than enough current! Decided to graph the TB motor circuit voltages, Everything looked OK. You'd think if I had a bad power/ground input to the PCM I would catch a glitch in the voltages.....Nothing. Checked the Alternator for bleeding AC voltage into the system....Nothing. Double checked the terminals at the PCM & TB with a magnifying glass....All Good. Re-Flashed the latest calibration into the PCM even though that had been done already.....Nothing, Pull hair out. I'm not one to get discouraged & irritated, But this car was testing me pretty good!.....Let it sit for a day while I caught up on making a paycheck for the week. Customer called a few times & I told the manager they can come get it & take it elsewhere if their in a hurry! Cleared my head & got back on it.....Used the oscilloscope portion of the Vantage Pro this time to monitor the TB Motor circuits. *Found a "Ghost" waveform while reviewing the WOT portion of the stored data right before the PCM cut voltage to the TB Motor. *Looked to be a Injector waveform, But Primary Coil control can look similar...... Unplugged the front 3 Injectors one at a time with no success. Unplugged #4 Coil.......SUCCESS!!!!! Installed a new Motorcraft Coil on #4 cylinder & test drove it for 17 miles with no symptoms or DTC's! [Linked Image]
 
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clinebarger

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Fort Worth, Texas
Originally Posted by OVERKILL
Excellent troubleshooting! Amazing that a faulty coil could take out the entire DBW system crzy
Still trying to wrap my head around it! The TB Motor Control circuits are a Twisted Pair to reduce interference, Ford maybe should have shielded it with a dedicated ground twisted with 2 motor control wires? No...The engine was not misfiring if anyone was wondering.
 
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2,926
Location
High Tax Illinois
Now that's some thinking!!! These new electronic stuffed cars/trucks are amazing. But.....WOW.....When they hiccup.....They can do all sorts of things!!! Great job a fix'in that thingy!!!!!!
 
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10,060
Location
Central Washington
Okay, thats it, I need to buy a o-scope. Thus far I have avoided buying DBW cars myself, but all my family does. I should ask did it look like the coil was a aftermarket replacement or was it original, etc?
 
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4,621
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Kuwait
I love reading through the different steps to troubleshooting like this, thank you for sharing! thumbsup Hope the customer can get their money back from the dealer for the TB and PCM!!
 
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Midwest, Illinois
In my line of business, twisted pair just doesn't cut it to shield noise. Twisted inside a ground braid, secured at both ends is usually a good solution. I have taken coax cable, stripped it, removed the center lead, compressed the braid to open it up and fished leads through it. Pull taught, ground both ends to shield. Excellent tech skills utilized here. Congrats.
 
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Messages
7,618
Location
California
Originally Posted by beanoil
In my line of business, twisted pair just doesn't cut it to shield noise. Twisted inside a ground braid, secured at both ends is usually a good solution. I have taken coax cable, stripped it, removed the center lead, compressed the braid to open it up and fished leads through it. .
Toyota is using coax cable for the knock sensor wiring on their cars for that reason alone - noise. They seem to be proponents of shielded cable for the in-car stuff though. Twisted pair seems to be a compromise to help reduce crosstalk and it's used for traditional CAN wiring like it's used for Ethernet but the twists in the cable seem to be more critical. Just like 80-conductor IDE cables when ATA66/100 was released in the late 1990s. I wonder how Ford is mitigating electrical noise in the coil/injector/DBW circuits - they are the noisest ones in a car.
 
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Wow, one would expect a misfire code somewhere in that bouquet of codes for a bad coil which would have made the diagnosis a breeze.
 
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10,060
Location
Central Washington
Originally Posted by Alfred_B
Wow, one would expect a misfire code somewhere in that bouquet of codes for a bad coil which would have made the diagnosis a breeze.
I believe the coil was still firing, just something was wrong internally causing a large amount of RF interference to be generated...enough to couple into the DBW wiring and upset the PCM. Something else I thought of is Ford generally fires their COPs multiple times per cycle, provided the RPMs are low enough to do that. Ive watched my car and it will spark 3 or 4 times in a row at idle. This is why they will idle baby smooth even with extremely worn spark plugs. If you saw such signal on the wiring it wouldve been a giveaway that it was a coil vs a injector.
 

clinebarger

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Fort Worth, Texas
No misfire symptoms were present, Mode $06 checked out as well. However......The throttle would cut before the engine/ignition system could be loaded. I still have the coil, I'll try to load it on a DBC Ford if I get the chance.
 

JC1

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Oshawa, Ontario Canada
Clinebarger excellent job! Can't blame you for taking a break in between troubleshooting to clear your head. How many hours labour did it take you to figure it all out?
 

JTK

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13,629
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Buffalo, NY
That is amazing and truly frightening. What would happen at a Ford dealer service department with this if one of the Techs hadn't been down this road before? Yikes. I've seem odd similar issues just due to low system voltage (weak battery, failing alternator, etc), but not electrical noise induced issues like this.
 
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10,060
Location
Central Washington
Originally Posted by JTK
That is amazing and truly frightening. What would happen at a Ford dealer service department with this if one of the Techs hadn't been down this road before? Yikes. I've seem odd similar issues just due to low system voltage (weak battery, failing alternator, etc), but not electrical noise induced issues like this.
Thats the problem, is they didnt, so the dealer threw a PCM and Throttle body at it and after not fixing it with $$$ in parts presumably the customer took it to the OPs shop. Lucky for the customer, he's through enough to catch this. I bet there are very few techs that could have figured this out.
 

JTK

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13,629
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Buffalo, NY
Originally Posted by Colt45ws
Thats the problem, is they didnt, so the dealer threw a PCM and Throttle body at it and after not fixing it with $$$ in parts presumably the customer took it to the OPs shop. Lucky for the customer, he's through enough to catch this. I bet there are very few techs that could have figured this out.
I hear you. It just wasn't clear to me if those components were replaced because of this issue or this issue cropped up after the replacements. I'm with you though. I'm sure there's outstanding Ford store techs out there, but rare.
 

clinebarger

Thread starter
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5,765
Location
Fort Worth, Texas
Originally Posted by JTK
Originally Posted by Colt45ws
Thats the problem, is they didnt, so the dealer threw a PCM and Throttle body at it and after not fixing it with $$$ in parts presumably the customer took it to the OPs shop. Lucky for the customer, he's through enough to catch this. I bet there are very few techs that could have figured this out.
I hear you. It just wasn't clear to me if those components were replaced because of this issue or this issue cropped up after the replacements. I'm with you though. I'm sure there's outstanding Ford store techs out there, but rare.
Yes, The PCM & Throttle Body were replaced by a Ford service department per the note on the service ticket. I don't know which dealer it was or what the actual situation was for the car to be towed to our shop. Some service department techs use "customer pay" jobs as an ATM machine, I'm not so sure that's what happen here.......This diag. had me scratching my head for a little bit!!! Hopefully the dealer just ate the cost of the parts, Waived the labor, And washed their hands on the car. I've only been in that situation once......With a early production 1997 Cadillac Catera right out of warranty, Thankfully we didn't replace any parts before we decided to wash our hands of it, And we "Frank Kent Cadillac" didn't sell the car new. Sometimes it's best for everyone involved, Once a mechanic gets irritated & upset......It's all downhill from there!
 
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