Ford Focus ST Forum banner
1 - 20 of 96 Posts

· Registered
Joined
·
44 Posts
Discussion Starter · #1 ·
I have a 2016 Focus ST. The car has an intercooler, intake, bags, and a cobb access port stratified tune loaded.

(Note: Previous owner removed fender liners and Vents installed into the hood that are operational)

I drove the car in the rain to work, went thru a large puddle very slowly and was fine. I started the car when I went to head home and engine fault warning popped up.
Throttle was very unresponsive and check engine light popped on. I limped the car 3 minutes home.
I let anything dry for about 2-3 days and still has the same problems even after clearing codes, pops back immediately.

In neutral and parked (clutch on and off), car will not rev at all: only idle, when off the clutch and in gear. The car will accelerate extremely slowly and wont go anywhere above 4k

My guess is the ECU could've gotten went. Has anyone experienced the same problem in the past?

Codes are P0303, P0316, P0453, P061B, P6A6, and P2122
 

· Super Moderator
2014 ST3. Garrett GTX2860R Gen 2. FBO
Joined
·
9,383 Posts

See post number 5.

Your ECU lives very close to the ground in front of the driver front tire. Start by disconnecting the battery and removing the PCM completely from the car. There is a little black rubber plug on the side of the PCM case. Pop that out and see if any water drains out. Dry the wiring connectors with compressed air (use keyboard duster in a can if you don't have a compressor). Also disconnect the throttle body connection and dry that out as well.

Start there and let us know
 

· Registered
Joined
·
44 Posts
Discussion Starter · #3 ·

See post number 5.

Your ECU lives very close to the ground in front of the driver front tire. Start by disconnecting the battery and removing the PCM completely from the car. There is a little black rubber plug on the side of the PCM case. Pop that out and see if any water drains out. Dry the wiring connectors with compressed air (use keyboard duster in a can if you don't have a compressor). Also disconnect the throttle body connection and dry that out as well.

Start there and let us know

I disconnected the battery and removed the ECU. I popped the top of the drain and no water came out. The housing area had a lot of sand and pebbles. I knocked most of it out and sprayed the connectors and ECU with Electronic Connector Cleaner. I let everything dry up and reinstalled it in the wheel well. I was unable to remove the Throttle Body Connection since I couldn't easily get to it but, it had dust around it and seemed to be bone dry.


I clear the codes and ONLY turn the car on and let it idle. I turn it off and get codes P0113 and P06A6. Once I turn the car on and give it gas, it says Engine Fault Service Immediately then the codes P0453 and P2122 appear. P06B8 will also appear.

Any advice and help is appreciated. I need to have to car back on the road to daily.
 

· Super Moderator
2014 ST3. Garrett GTX2860R Gen 2. FBO
Joined
·
9,383 Posts
How Handy are you with a volt meter?

I'll save you as much time as possible. Do the tests exactly as outlined in this thread below.

The pinouts are on page 1 and the instructions for testing start on page 2. Follow them exactly and then report back here what you found. You should be able to do this all in an hour or 2.


Pro tip- if you do not have back probes (to check voltage with the connection plugged in) then you can use a sewing needle with some WD-40 sprayed on it to prove through the weather pack.
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
P06A6 is a short on a 5 volt signal for one of the VREF.

P0113 is the IAT (intake air temperature) sensor not working.

P2122 low voltage to the throttle body

P06B8 is a PCM NVRAM error.

The biggest thing here somewhere something is shorted on the 5 volt side.

How big of a puddle are we talking here?
 

· Registered
Joined
·
44 Posts
Discussion Starter · #6 ·
P06A6 is a short on a 5 volt signal for one of the VREF.

P0113 is the IAT (intake air temperature) sensor not working.

P2122 low voltage to the throttle body

P06B8 is a PCM NVRAM error.

The biggest thing here somewhere something is shorted on the 5 volt side.

How big of a puddle are we talking here?
The puddle was a collection of water on the road maybe up to 3-4 inches deep. I drove super slow thru it because I knew I had no fender liners. It was my only route into the work parking lot. I was also fully aired up with the bags and not low to the floor at the time
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
The puddle was a collection of water on the road maybe up to 3-4 inches deep. I drove super slow thru it because I knew I had no fender liners. It was my only route into the work parking lot. I was also fully aired up with the bags and not low to the floor at the time
Time to start pulling sensor connectors and checking for water intrusion.
 
  • Like
Reactions: rob99rt

· Registered
Joined
·
44 Posts
Discussion Starter · #8 ·
Time to start pulling sensor connectors and checking for water intrusion.
What all connectors do you recommend I check? I also found some water in the spare tire area because the previous owner drilled holes for the air lines. (Will be sealing that soon) And found water in the cabin in the back seat floorboard. Unsure how exactly it flowed in. I live in Phoenix, AZ so I never expect it to rain.
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
You're going to need to start with the anything low. Intercooler, crankshaft pickup, anything that the water touched. Don't forget that your entire charcoal cannister probably took a bath as well. It has a vent valve that's controlled by the PCM.
 

· Registered
Joined
·
44 Posts
Discussion Starter · #10 ·
You're going to need to start with the anything low. Intercooler, crankshaft pickup, anything that the water touched. Don't forget that your entire charcoal cannister probably took a bath as well. It has a vent valve that's controlled by the PCM.
Its night time here so I wont be working on it and its raining tomorrow. Do you recommend I check the connector or shake out the entire charcoal canister? I am unsure where its located.
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
Its night time here so I wont be working on it and its raining tomorrow. Do you recommend I check the connector or shake out the entire charcoal canister? I am unsure where its located.
The charcoal cannister is under the vehicle near the rear of the fuel tank.
Automotive tire Vehicle Motor vehicle Hood Bumper


If you think this went under water (submerged) for any period of time you may want to check it. I fairly certain that you're dealing with water intrusion but items like this always go over looked.

Start focusing on the front engine harness. The DTC'S are pointing towards a short of a 5 VDC bus. The sensors in your car run off of a 5 VDC power source provided by your PCM. This is indicated by labels on the wiring diagrams.

VREF = 5 + (power), SIGRTN = 5 - (ground)

Some sensor use only a SIGRTN such as the IAT (intake air temperature) whereas others use all three wires (power, ground & signal return back to the PCM) such as the MAP (manifold absolute pressure) sensor located on you intake manifold.

Here's a more detailed explanation

Start looking for any sensor that could have been submerged. I'm glad to hear that the PCM seemed dry when you're ready and if you have a DMM we can start checking PCM outputs to try and find what may be shorted.

J
 

· Registered
Joined
·
44 Posts
Discussion Starter · #12 ·
The charcoal cannister is under the vehicle near the rear of the fuel tank.
View attachment 412850

If you think this went under water (submerged) for any period of time you may want to check it. I fairly certain that you're dealing with water intrusion but items like this always go over looked.

Start focusing on the front engine harness. The DTC'S are pointing towards a short of a 5 VDC bus. The sensors in your car run off of a 5 VDC power source provided by your PCM. This is indicated by labels on the wiring diagrams.

VREF = 5 + (power), SIGRTN = 5 - (ground)

Some sensor use only a SIGRTN such as the IAT (intake air temperature) whereas others use all three wires (power, ground & signal return back to the PCM) such as the MAP (manifold absolute pressure) sensor located on you intake manifold.

Here's a more detailed explanation

Start looking for any sensor that could have been submerged. I'm glad to hear that the PCM seemed dry when you're ready and if you have a DMM we can start checking PCM outputs to try and find what may be shorted.

J
I assume I should just go straight into checking all the test points with a multimeter. I checked out the charcoal canister and it seemed pretty bone dry with no signs of water collecting at the bottom and drying out nor did I see an electrical connector near that area. I managed to remove the TB connection to see it was dry and cleaned it but can't get it back on properly. This car is starting to put me thru the ringer so I just want it over with.
 

· Registered
Joined
·
44 Posts
Discussion Starter · #13 ·
I assume I should just go straight into checking all the test points with a multimeter. I checked out the charcoal canister and it seemed pretty bone dry with no signs of water collecting at the bottom and drying out nor did I see an electrical connector near that area. I managed to remove the TB connection to see it was dry and cleaned it but can't get it back on properly. This car is starting to put me thru the ringer so I just want it over with.
With the amount of trouble codes I have. I almost want to believe the PCM got moisture in it somehow and is causing all the issues. After checking the PCM connection again, some pins had some a very light shade of brown like corrosion could be starting to show. I have these codes

P0113
P0453
P068A
P06A6
P06B8
P2122
 

· Registered
Joined
·
44 Posts
Discussion Starter · #14 ·
How Handy are you with a volt meter?

I'll save you as much time as possible. Do the tests exactly as outlined in this thread below.

The pinouts are on page 1 and the instructions for testing start on page 2. Follow them exactly and then report back here what you found. You should be able to do this all in an hour or 2.


Pro tip- if you do not have back probes (to check voltage with the connection plugged in) then you can use a sewing needle with some WD-40 sprayed on it to prove through the weather pack.
Been awhile...

I performed all the tests and compared them to the readings that they should be according to that thread. This is my finding

I found APP pins 1 & 3 read 14+ volts
BJB Pin 18 read 14+ volts

I know both of those should be at 5 volts like I was getting on APP pins 4 & 6.
Removed the BJB plug to isolate to the PCM. found I was getting perfect continuity on APPVREF1 with no issues.
It appears there is a short from BJB Pin 28 to the PCM pin 36 for APPRTN1.

My other DTC's are P0453 and P06A6 so I suspect the short is somewhere near where Fuel Tank pressure sensor meets PCM to BJB path in the harness. Please let me know if I am safe to assume this. I will be taking another look at it and tracing down the short since I know have the wire secluded.
 

· Super Moderator
2014 ST3. Garrett GTX2860R Gen 2. FBO
Joined
·
9,383 Posts
Were these readings achieved with the APP unplugged, or backprobed while plugged in?

It definitely seems like a short, but its to battery voltage. If there was a short from bjb pin 18 to pcm c1381b pin 36, it would just read 5v on a normally operating system.
Is battery voltage displayed on these wires key-on only, or is at all times?

If you unplug both connectors of the PCM as well as the APP, reconnect the battery and power the car up, do you still have 12v on these wires?
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
Short to ground (copper on steel)
Short to voltage (copper on copper)
 

· Registered
Joined
·
44 Posts
Discussion Starter · #17 ·
Were these readings achieved with the APP unplugged, or backprobed while plugged in?

It definitely seems like a short, but its to battery voltage. If there was a short from bjb pin 18 to pcm c1381b pin 36, it would just read 5v on a normally operating system.
Is battery voltage displayed on these wires key-on only, or is at all times?

If you unplug both connectors of the PCM as well as the APP, reconnect the battery and power the car up, do you still have 12v on these wires?
These readings were achieved with both the APP plugged and unplugged.

the battery voltage is display only with the key on. once its off the reading drops down to 0 volts.

When I unplug both PCM connectors and the APP. I do not get a voltage reading from pin 18.

I also had gone ahead and randomly pulled the trigger on an replacement PCM and had it programmed to try and eliminate that as a possibility since it was in the back of my mind. So the PCM gives the same DTC's between the original and replacement.

I am unsure of what the next step to do is.
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
These readings were achieved with both the APP plugged and unplugged.

the battery voltage is display only with the key on. once its off the reading drops down to 0 volts.

When I unplug both PCM connectors and the APP. I do not get a voltage reading from pin 18.

I also had gone ahead and randomly pulled the trigger on an replacement PCM and had it programmed to try and eliminate that as a possibility since it was in the back of my mind. So the PCM gives the same DTC's between the original and replacement.

I am unsure of what the next step to do is.
Be extremely careful pluging in a replacement PCM until you find the fault or you risk potential damage.
 

· Super Moderator
2017 Kona Blue ST1
Joined
·
5,403 Posts
I was told it doesn't matter how I plug it in as long as the ignition isnt on.

I am just waiting for some advice from TurboGT at the moment. I do not know what to start tracing next.
Cool, just a word of caution that's all.
 
1 - 20 of 96 Posts
Top