Code P068A after bov install (SOLVED)

[Wyatt4944]

i installed the bov and everything was going good but u took it off and ceaned the contact area of it and now i got a pcm too early code p068a runs fine and works but now i cant shift into drive unless i manually push the release and i just change the break plunger

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[OGMix376]

Is it possible your battery could be going bad and this code coming on right after installing the bov could be a crazy coincidence?
I just did this yesterday and drove the truck almost 300 miles since then and haven’t had any issue.
Hopefully airline tech will come save the day like he always does.

 

[Wyatt4944]

Is it possible your battery could be going bad and this code coming on could be a crazy coincidence?
I just did this yesterday and drove the truck almost 300 miles since then and haven’t had any issue.
Hopefully airline tech will come save the day like he always does.

my bat reads 15vs at idle i checked every single fuze and relay and it wont let me put it into drive

 

[OGMix376]

Did you disconnect the battery when swapping the BOV?
Possibly a loose terminal on the battery if you did.. might be tight but not tight enough if you say hit a speed bump at fun speeds could still jiggle it and cause the robots to get mad.. unless the code came on right at start up after installing and reconnecting… honestly idk past this.. I’m not good with electrical computer stuff.

 

[Wyatt4944]

Did you disconnect the battery when swapping the BOV?
Possibly a loose terminal on the battery if you did.. might be tight but not tight enough if you say hit a speed bump at fun speeds could still jiggle it and cause the robots to get mad.. unless the code came on right at start up after installing and reconnecting… honestly idk past this.. I’m not good with electrical computer stuff.

i did not disconnect the bat when i put on the bov i took off the bov thwn i put it back on that is when the code came on when i push my start buddon my dash goes black then when i click it again it starts bu

 

[OGMix376]

Sorry I’m not much help. Hope someone has a solution for you. Good luck brother.

 

[airline tech]

I am assuming you installed, started the engine or cycled the key.
Then shut off the truck - How Long did you wait before you pulled the connector on the By-Pass Valve?

The PCM Power Relay feeds Fuse #12 - Fuse #12 Feeds the By-Pass Valve
The code P068A - One of the causes is the PCM Power Relay, deenergizes too early or a issue with the Power Relay and the ISP-R (Ignition Switch Position-Run) circuit.

I am thinking that these are the possibilities.
1. The By-Pass Valve is internally shorted and back feeding up to the PCM Power Relay
2. The Connector or nearby wiring was damaged
3. The Disconnect and or Re-Connect of the connector (with active power on the relay) shorted the PCM-Power Relay and or damaged Fuse #12 (Partially Blown) or the BJB - Engine Bay Fuse Box was shorted (Feeding the PCM Power Relay)

I would try:
1st - Inspect the By-Pass Valve connector and the harness that you had your hands on for any damage.
2nd - With the Scan Tool - Clear the code & do a PCM Self-Test - Reset
3rd - Relace the PCM Power Relay & Fuse 12
4th - Install the OE By-Pass valve and perform step 2 again

There is a lengthy (T-Shoor) wire checks for this code, but I am only traveling down the path for what you have touched at the moment.
Note: One of the items on that power circuit is the Trans Fluid Heater Cont Valve, I am thinking this (Circuit) anomaly on that valve is taking it down and the side effect of that is -The truck will not shift out of park.

P068A: ECM/PCM Power Relay De-Energized - Too Early

As I stated - The Code (T-Shoot) takes you down a path that only focuses on the (PCM Power Relay) and (ISP-R) circuits.
Since you were on the (Fuse #12) power circuit which feeds off the PCM Power Relay (after is closes)
I think it's best to focus on that circuit and possibles that may have been generated by your actions, or the By-Pass valve itself is causing the issues.
So, either something in the circuit is shorting preventing the PCM Power Relay to function properly or the PCM has locked in a code for abnormal power across it and needs the PCM Self-Test to clear it.

Just to confirm - You did not perform any of actions on the truck such as Tune etc
Another option would be - Disconnect the Battery for 10-Minutes or so if all of the above fails.

Worst case scenario here is the PCM circuit controlling the By-Pass valve is fried, hopefully this is something simple and easily recovered without condemning the PCM if it comes down to unable to recover with the simple things then it's a in-depth wire check to find the issue.
As something is not allowing (ISP-R) to be transmitted to all modules, this is the reason why the Ignition (start) is not normal and not shifting out of park.

 

[airline tech]

I can see the possible reason for - Not shifting out of park and Ignition Switch (Issues)

Check Fuse #8 - It feeds the Shift Lever; Fuse #11 Feeds the injectors (engine runs so it's good)
But the diagram below shows how the By-Pass valve and or wiring associated can be affecting power to Fuse #8 and Fuse #7.
Fuse #7 feeds the PCM (VPWR) This ties in the (ISP-R) and this is the reason for the code you have. (PCM Power Relay - Deenergized Too Early)
So, it's a power disruption on this circuit.

Fuse #8 - Feeds the Shift Lever - This is the reason for not shifting out of park - again Power Disruption

It boils down to, is it just a locked code and needs cleared or is it a current code and the circuits are being disrupted by a short in the wire harness or internal short in the By-Pass Valve
voltage drop.

With KOEO- (Key On Engine Off) meter across all of these fuses
7-8-11-12
Note: The reading - they all should be showing battery voltage, I have a feeling Fuse's 7 & 8 are not getting the proper voltage

To check my assumption. (If a noted voltage reading issue)
Across all fuses: 7-8-11 and 12 - check as follows

Disconnect the By-Pass Valve (Connector) - Did voltage return?
If Yes - The By-Pass Valve is internally shorted
If No - Reconnect and wiggle the connector and shake the harness- Did voltage fluctuate?
If Yes - It's in the harness or connector, the wires are touching each other.

 

[RangerBill]

i installed the bov and everything was going good but u took it off and ceaned the contact area of it and now i got a pcm too early code p068a runs fine and works but now i cant shift into drive unless i manually push the release and i just change the break plunger

By change the break (brake) plunger, do you mean the master cylinder to brake pedal rod? If so, you may have done something to the brake pedal on/off switch activated by the brake pedal. This would cause your problem with not being able to shift into drive. The BOO switch as it is called, may be out of position or need adjusted. Also check the wiring to this switch for damage.

 

[Wyatt4944]

I can see the possible reason for - Not shifting out of park and Ignition Switch (Issues)

Check Fuse #8 - It feeds the Shift Lever; Fuse #11 Feeds the injectors (engine runs so it's good)
But the diagram below shows how the By-Pass valve and or wiring associated can be affecting power to Fuse #8 and Fuse #7.
Fuse #7 feeds the PCM (VPWR) This ties in the (ISP-R) and this is the reason for the code you have. (PCM Power Relay - Deenergized Too Early)
So, it's a power disruption on this circuit.

Fuse #8 - Feeds the Shift Lever - This is the reason for not shifting out of park - again Power Disruption

It boils down to, is it just a locked code and needs cleared or is it a current code and the circuits are being disrupted by a short in the wire harness or internal short in the By-Pass Valve
voltage drop.

With KOEO- (Key On Engine Off) meter across all of these fuses
7-8-11-12
Note: The reading - they all should be showing battery voltage, I have a feeling Fuse's 7 & 8 are not getting the proper voltage

To check my assumption. (If a noted voltage reading issue)
Across all fuses: 7-8-11 and 12 - check as follows

Disconnect the By-Pass Valve (Connector) - Did voltage return?
If Yes - The By-Pass Valve is internally shorted
If No - Reconnect and wiggle the connector and shake the harness- Did voltage fluctuate?
If Yes - It's in the harness or connector, the wires are touching each other.

I have checked every single fuse with the key on engine off and they are all getting power with the bov plugged in using a multimeter and all are fine i cleared the code with my scanner and it still is there just no engine light my break lights are not working I even bought a new battery there is no tune on the truck

 

[Wyatt4944]

I can see the possible reason for - Not shifting out of park and Ignition Switch (Issues)

Check Fuse #8 - It feeds the Shift Lever; Fuse #11 Feeds the injectors (engine runs so it's good)
But the diagram below shows how the By-Pass valve and or wiring associated can be affecting power to Fuse #8 and Fuse #7.
Fuse #7 feeds the PCM (VPWR) This ties in the (ISP-R) and this is the reason for the code you have. (PCM Power Relay - Deenergized Too Early)
So, it's a power disruption on this circuit.

Fuse #8 - Feeds the Shift Lever - This is the reason for not shifting out of park - again Power Disruption

It boils down to, is it just a locked code and needs cleared or is it a current code and the circuits are being disrupted by a short in the wire harness or internal short in the By-Pass Valve
voltage drop.

With KOEO- (Key On Engine Off) meter across all of these fuses
7-8-11-12
Note: The reading - they all should be showing battery voltage, I have a feeling Fuse's 7 & 8 are not getting the proper voltage

To check my assumption. (If a noted voltage reading issue)
Across all fuses: 7-8-11 and 12 - check as follows

Disconnect the By-Pass Valve (Connector) - Did voltage return?
If Yes - The By-Pass Valve is internally shorted
If No - Reconnect and wiggle the connector and shake the harness- Did voltage fluctuate?
If Yes - It's in the harness or connector, the wires are touching each other.

I found another code U0100-00

 

[airline tech]

I have checked every single fuse with the key on engine off and they are all getting power with the bov plugged in using a multimeter and all are fine i cleared the code with my scanner and it still is there just no engine light my break lights are not working I even bought a new battery there is no tune on the truck

Ok, I am somewhat confused on - Timeline of Maintenance Actions and what the reason was for.

Sorry, I missed in your original post - which @RangerBill caught, you replaced the (Brake Plunger - Thingy) I am assuming you mean the (Brake Pedal Position) Switch
and
Have replaced the By-Pass Valve with an aftermarket (BOV)

Which one was done first?
And what was the original reason for replacing the (Position) switch?

You have also stated you have a new battery - When was that Replaced?
How long ago?
This may be the reason for the code, if the PCM Power Relay just happened to be energized when you disconnected the battery. (Possible)

I am assuming (recently replaced) the Brake Pedal Position Switch for non-working brake lights; you fixed the issue and then later wanted to upgrade the (BOV) mod and now have the (Code-Message) and your brake lights stopped working again and have another added issue and that is unable to shift out of park. - Is this timeline of maintenance actions - Correct?

Note: In my previous post I was under the impression the - unable to shift out of park and code issue only came after the BOV install, that is why I focused on everything that was physically toughed.

I am trying to pinpoint down how they all tie together and also give you that code.
I know that the code is telling us that the PCM Power Relay was opened when it should be closed.

So, this means

Power was lost on the - Coil Side of the relay and it opened, this ties into the Wake Circuit and ISP-R Circuit. (What triggered it to open?) Power Loss, Ground Loss or Short
or
Voltage anomaly back feeding on the output side of the relay.

With the new information - Lets focus on the Brake Lights and (Shift) out of park issue
With the switch being replaced, I do not see any kind of adjustment in the manuals for it like others that I have replaced, and it just mounts in a bracket with a 1/4 turn lock in place mounting.

This switch is the: Stop-Lamp Switch or Brake Pedal Position Switch (same thing) it outputs 2 signals
BOO - Brake Pedal On/Off & Brake Force for the ABS System

The Brake Pedal - BOO output is sent to the BCM, this output is also sent via the BCM on another circuit to the Brake Shift Interlock Actuator (This is what prevents shifting) out of park unless the brake pedal is applied.

With the Brake Lights & Shift Interlock not working we need to verify the Brake Light Switch is working and has power to it:

Fuse #47 Feeds the Switch
Fuse #47 is a 3-Leg Fuse, and it covers Fuse 46 & 47 - With Fuse #46 being (Not Used)
The center leg feeds both sides of the fuse, ensure you are getting power between the center leg and #47 leg, it's better to pull & inspect it.
If fuse is GOOD, then we need to move to the switch connector C278

Ck Pin #1 to Body Ground - Shold have power, if no then we need to T-Shoot reason
FUSE JUMPER (10-Amp) - Pin #1 & Pin #4 - Brake Lights Should be on and also allow to shift out of park this is by-passing the switch
If the jumper cures the issue - Replace the Switch
If it does not, then we need to T-Shoot Reason
Note:
Pin #1 = Power from fuse 47
Pin #2 = Brake Force Signal (Output to PCM) This this the (Cruise Control) Deactivation Signal
Pin #3 = Ground - Ground for Pin #2
Pin #4 = Brake On/Off Signal (Input to the BCM)

The Ground for Pin #4 is provided by the BCM, so when you jumper Pin 1 to Pin 4 you are completing the power (side) feed to the BCM and then the BCM provides the ground path.

C278 - Brake Pedal Position Switch

There are more in depth wire checks that need to be performed if the above does not resolve the issue.
Plus, I noted you have Scan Gauge, will it perform more functions than Read & Clear codes?

Ref: The PCM Self-Test - Can it do it? if not Forscan can
The Self-Test is more than a code reset, that is what needs to be done to get the code out of the memory (if it is not an active) fault it will clear the code.
Forscan can also display - Live Data PID's although it is a challenge to get the the PIDs you want to view to display.
We need to view Brake Switch Inputs and all power (Input) module voltages
I do not use Forscan for any T-Shoot for this reason, it's very limited for T-Shoot but GREAT for altering (As-Built) data

A High-End scan tool can do this and more (as we also need) Bi-Directional control, which Forscan does not have.

We need to get into the system and command inputs for the Brake Lights & Brake Shift Interlock and also command the relays open & closed.
It is much easier to isolate what is happening with a better scan tool.
By using the Active Test or Bi-Directional Control to control various outputs.
I have 4 scan tools - I would have to hook up and see which one has the control to command the Brake Shift Interlock (actuator) I think it's my Top-Don, I think they all can trigger the Brake Lights on as well command the relays (open & closed)


I want to HIGHLIGHT something for you.
Note how the PCM Power Relay (Coil-Power-Input) is Shared with the output power circuit.
ANY Voltage anomaly (short) on the output circuit could trigger the (coil side) to open in the event of a short, I strongly feel that this is what caused the code to trigger.
Reason the coil power side is waiting for a ground:

When the BCM (Receives ISP-R) it sends the signal to the PCM to apply the ground to the PCM-Power Relay. When this happens the relay closes.
If we look at this in a (non-normal) view and think (What-IF) we had a short to ground on any of the power (output) circuits, but it was not long enough or drastic to blow the fuse it would momentarily provide a (SHORTCUT) path to ground prior to reaching the (Relay Coil) thus removing the coil power.
I am highly certain this is what caused the code, now was it momentary or is it still an issue, the truck runs so the relay is closing - but we will need to dig deeper into this, if the PCM Self-Test reports this as an active fault, if this is the case I suggest putting the OE By-Pass valve back in and see if the code goes away.

A simplified diagram visual for what I am talking about:
Picture Pin#1 jumped straight to body ground; this takes away the power for the relay coil except the ground came from the BOV Internally or the wires feeding it.
Do you understand why I am venturing on this path?


To be honest here, if you do not have the proper scan tool to do the needed tests.
I would put the OE Valve back in and see what the outcome is, my gut is telling me the issue is in the BOV, pulling down the circuit.

Edit:
What Module is reporting the U0100:00 Code?
That is a generic code that covers more than one module.

 

[Trigganometry]

I had this happen to me long ago. On the BOV where the shrink wrap to wire is there is a small molex connector under the shrink wrap. See if you can push the wire stem and shrink wrap into the BOV head to be sure that connector is seated.

 

[RangerBill]

I have checked every single fuse with the key on engine off and they are all getting power with the bov plugged in using a multimeter and all are fine i cleared the code with my scanner and it still is there just no engine light my break lights are not working I even bought a new battery there is no tune on the truck

A bad, disconnected, misadjusted, or bad wiring to the BPP brake pedal position switch would also cause the brake lights to not work as well as the shifter lock out symptoms. Also check fuse 47 in the battery junction box.

 

[airline tech]

i did not disconnect the bat when i put on the bov i took off the bov thwn i put it back on that is when the code came on when i push my start buddon my dash goes black then when i click it again it starts bu

Question:
Did by chance was the TCU commanding an update of health check at this moment?
You will know what I am talking about if you have ever been near the truck and you all of a sudden hear the- Waste Gate Actuator - Self Test (Cycle)
The PCM Power Relay has to be closed for that to happen and it self-times out in 3-minutes (opens)
and or
Did you disconnect the By-Pass valve connector shortly after opening / closing the driver's door.
I am thinking a deeper in-depth diagnosis that coincides with my above theory (short)
that the PCM Power Relay had power on it at the time you disconnected the connector.
The wiggling of the connector and or the power break when it was disconnected, back fed the relay and it - opened the coil power control, before the PCM commanded to remove the ground for it.
(Too Early-Code)

This would explain why it coded at this time and explain why you had an issue with the PB Start Cycle - The PCM was lost as it still had a commanded (Ground) on the relay and it took a (Key Cycle) to get it back in sequence.
So as long as the (PB Start issue) only happened the first start cycle - this may just be a Fluke of bad timing.
If you are still having (PB-Start) issues along with the Brake Ligh issue, then we need to address this.

So, I am leaning more towards this just being a Fluke - bad timing of events that triggered the code.
But to possibly help in diagnosing (if the BOV) itself is causing it, we can try checking the internal resistance of the (Components) BOV & By-Pass valve.
This will at least give an idea if the BOV is internally causing the issue.

Ohms Scale:
Measure between Pins 1 & 2 on both valves - to be accurate have them at the same temperature
(ambient)

Should be: 5-60 Ohms - This is the spec from the manuals, if the new (BOV) is considerably higher than the (OE) valve or out of these specs - I would say the BOV is highly suspect.

I am also thinking that you have 2 separate issues here that just happened to show up at the same time vs my initial though of them being tied together, they still can be-but we need to tackle the (Brake Light) issue first - Most Important and then see if we can get the relay code to clear.

Also, the Brake Pedal Position switch, from what I can tell does not have an (Install Adjustment) it just mounts on a bracket (1/4 Turn) lock in place.
This is different than older style of switches where you had to adjust them.

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