Transmission not shifting?

Tiny
BENOIT EMAN
  • MEMBER
  • 2015 CHEVROLET IMPALA
  • 2.5L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 68,000 MILES
The 305F is most certainly the aux battery that is waiting for replacement. I even disconnected the negative cable on the aux battery, but strangely enough the car did automatically shut off and star back again today. The P16CF however, I already changed the intake solenoid, which did clear the code. After changing the solenoid, I could floor it and it shifted gears smoothly. Before the change, when I floor it, it did not change gears in high rpm, I had to lessen the gas, and then it shifted. Any insight? Ben
Saturday, April 25th, 2020 AT 10:24 PM

20 Replies

Tiny
KASEKENNY
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I attached the TSB for the P305F for you to review. I also attached the testing for the P16CF. I am not sure the.3ohm number is correct because I don't see that as part of this testing. I suspect you have a wiring issue but running through this test will prove out what the issue is.

Run through all of this and let me know what questions you have.
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Sunday, April 26th, 2020 AT 5:27 PM
Tiny
BENOIT EMAN
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Best Kenny,

Thank you so much for your input.

Regarding p16cf, on the 6th attachment, title Conditions for setting DTC, I don't get that, how do I do that? What is 2.5s?
I have a regular odb2/eobd Foxwell nt301 scan tool, not sure if that does the job?

Benoit
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Monday, April 27th, 2020 AT 9:16 PM
Tiny
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What this means is the ECM is commanding a specific position of the actuator and it also monitors the actual position. So when the commanded and actual positions are not the same for more then 2 and a half seconds it sets the code.

From what I can tell that scan tool can look at live data (see screen shot) so I would think it can see the data needed to monitor which is the second screen shot.
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Tuesday, April 28th, 2020 AT 5:54 PM
Tiny
BENOIT EMAN
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Dear Kenny,

I finally got the new aux battery from overseas and installed it. The car started auto-stopping at every red light. The code wasn't there anymore. Not for long, it come back one and it only sometimes auto-stops the engine at a red light. I don't understand the negative cables are not loose. Same goes for the p16cf. I put 12v direct on the intake control solenoid, and it works. If I leave it disconnected, the car starts but shuts off in 2 seconds. I also drained the transmission oil, only 4.5 quarts came out, and that's starting the engine twice for 5 seconds with the drain open to empty the converter. The fluid was dirty black. I put 6 new quarts in it. When I clear the codes, the car shifts smoothly when I floor it. When the code is back on, it doesn't, it get stuck in 1st. This is only when flooring it. I sometimes feel the car hesitating a bit. Like something wring with transmission, but guess it has to do with the valve lift stuck on high, which is the problem of p16cf. Sometimes it stays in 1st too long if I don't touch the gas pedal.

Any ideas?
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Sunday, May 17th, 2020 AT 11:32 PM
Tiny
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So if this is happening in WOT then I suspect the ECM is seeing the issue causing the shifting issue as well. Did you run through all the diag for the code? If not, we need to do that or we will just be going in circles.
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Monday, May 18th, 2020 AT 7:50 PM
Tiny
BENOIT EMAN
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Kenny,

Km stuck at page 8 circuit/system testing.

Q25 rocker arm solenoid valve is the intake one right? On the cabin side.

Which are control circuit 1 and 3?
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Thursday, May 28th, 2020 AT 10:26 PM
Tiny
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That is correct. Your code was for the intake. I attached the connector view so you can see which circuit is which.
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Friday, May 29th, 2020 AT 7:25 PM
Tiny
BENOIT EMAN
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Kenny, good day good week.

Thanks for he reply.

This is the discontinued part?

There is some confusion between two parts, both sharing the terms actuators/solenoids/rocker arms.
This one with 3 pins, ut be the discontinued part that attached on the back of the head.
There are also two, two-pin connectors which are for the solenoids, one for intake and one for exhaust.

Do you have a schematic of what/where q25 is?

I notice that most of the time, the transmission does not shift when I floor it, it get stuck just before shifting. It does however sometime shift.

I changed the transmission oil, I didn't changed the filter though.

The oil life says 70% in the dash, so I didn't change that yet.
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-1
Monday, June 1st, 2020 AT 7:12 AM
Tiny
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I have attached the info on this. The actuator/solenoid is the same thing. If the part is discontinued then your only option is to try and find one used from a salvage yard or online.
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Monday, June 1st, 2020 AT 7:19 PM
Tiny
BENOIT EMAN
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Kenny good afternoon, thanks for the reply,

That what is highlighted in red is the vvt sprocket, I thought the instructions is referring to either this

https://www.rockauto.com/en/catalog/chevrolet,2015,impala,2.5l+l4,3308756,engine,variable+valve+timing+(vvt)+solenoid+/+actuator,12910

or this

https://www.rockauto.com/en/partsearch/?partnum=12633613

a bunch of threads point to these two parts

How can the sprocket be tested? It doesn't have electrical connections, or does it?

Thanks
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Tuesday, June 2nd, 2020 AT 2:36 PM
Tiny
BENOIT EMAN
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Kenny good afternoon,

The highlighted part is the VVT sprocket, not actuator nor solenoid.

Maybe you uploaded the wrong image?

If I'm not mistaken, the sprocket does not run electricity through it, so I could not test it right?
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Sunday, June 7th, 2020 AT 11:55 AM
Tiny
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The actuator/solenoid is on the front of the sprocket which is highlighted. I attached a picture of the solenoid/actuator. Number 1 is the electrical connector and number 2 is what goes into the camshaft and through the sprocket.
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Sunday, June 7th, 2020 AT 5:31 PM
Tiny
BENOIT EMAN
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Kenny thanks for the reply.

That actuator, has only 2 pins, that one I already changed, but the code came back again, so I bought another one, but did not change it yet, as I need to know why it keeps pulling up the p316cf code.

The actuator one attached on the back of the head, that one has 3, its a discontinued part, they sell them for around $400.00 ti $500.00 on eBay item number 383553971972.
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Sunday, June 7th, 2020 AT 9:12 PM
Tiny
BENOIT EMAN
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This one:
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Sunday, June 7th, 2020 AT 9:13 PM
Tiny
KASEKENNY
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Okay. The picture that you just posted is for the rocker arm control valve. That is the testing that I posted earlier and to this post as well and is for the P16CF. However, if that tests okay then the issue is with the oil control valve which is what I posted on the post prior to this one.

These are all actuators/solenoids so I think we are getting caught up by that term.

So for this code we need to go through this testing because if you have replaced the control valves then they are most likely not the issue and you have a wiring issue.

So run through this test and let me know what you find. Thanks
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Monday, June 8th, 2020 AT 7:35 PM
Tiny
BENOIT EMAN
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Dear Kenny,

I now also have the p16d0 code along with the p305f which sometimes is on, sometimes not. Do you maybe recommend another strategy now?

Thanks,

Ben
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Saturday, June 27th, 2020 AT 10:47 AM
Tiny
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Unfortunately it does not. These are all related to one another. I attached the info for this P16d0. As you will see, you are doing basically the same testing which is what we need to do. We need to remove the solenoid and inspect the screen for metal debris because if you have this then the bearing material may be causing all your issues.

Have you drained the oil and checked it for metal? If not, let's do that because metal floating through the system will cause what you are seeing.
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Saturday, June 27th, 2020 AT 7:39 PM
Tiny
BENOIT EMAN
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Kenny good day.

I had the car scanned at a shop who has the good scanners, they told me I had to replace the exhaust VVT solenoid

Now I want to change it along with the oil and oil filter, but I want to change the screen for the solenoid as well, do you know where it is located?

i'm referring to this filter screen:

https://www.youtube.com/watch?v=fPqjJVHZS3I&t=29s
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Saturday, July 18th, 2020 AT 11:56 AM
Tiny
BENOIT EMAN
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Should I use a slightly heavier oil? I read it's suppose to use 5w20.
Here we mostly have 10w20 or 10w30 though. It's 30 degrees Celsius everyday here in Aruba.

Also should it be full synthetic or can it also be semi or conventional oil?
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Saturday, July 18th, 2020 AT 11:58 AM
Tiny
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Here is the process from the manual for the solenoid. As for the oil, I attached what is should be and yes it should be 5W-20. If you are using a heavier oil, that can cause issues on these variable valve vehicles. So I would suggest sticking with what it calls for.

Thanks
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Saturday, July 18th, 2020 AT 7:15 PM

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