Hi All,
I'm an owner of a 2018 Honda Accord 1.5 that is suddenly having a cascading series of issues. After 5 years of no problems, one morning I had every warning light trigger (engine, power steering, brakes, etc.) and hesitation when accelerating at higher speeds. When reading the codes, I had the following:
P2651 [0x2651]
Rocker arm actuator B, bank 1 - performance problem or actuator stuck off
Status: Confirmed
----------------------------
P2651(00) [0x265100]
Rocker arm actuator B, bank 1 - performance problem or actuator stuck off
Status: Pending, Confirmed, Test not completed during this operation cycle, Warning indicator requested
============================
Engine #2Engine #2
DTCs: 1
----------------------------
P2651(00) [0x265100]
Rocker arm actuator B, bank 1 - performance problem or actuator stuck off
Status: Pending, Confirmed, Test not completed during this operation cycle, Warning indicator requested
============================
ABSABS
DTCs: 1
----------------------------
U0401(68) [0xC40168]
Invalid data received - engine control module (ECM)
Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear
============================
SRS
No DTC found.
============================
EPSEPS
DTCs: 1
----------------------------
U0416(68) [0xC41668]
Invalid data received - vehicle dynamics control module
Status: Test failed (current drive cycle), Pending, Confirmed

I took my vehicle to Russel and Smith Honda Dealership in Houston and they diagnosed that the oil control solenoid had to be replaced and cost $565, which I authorized. Two weeks later, every warning light triggered again. I took my vehicle back to the same dealer and they stated that the rocker arm had to be replaced and cost $480, which I authorized. The same day I received my vehicle back, when accelerating on the freeway, I suddenly lost power and every warning light triggered. When reading the codes, I had the following:
P0303 [0x0303]
Cylinder 3 - misfire detected
No. 3 Cylinder Misfire
Status: Confirmed
----------------------------
P0303(00) [0x030300]
Cylinder 3 - misfire detected
No. 3 Cylinder Misfire
Status: Test failed (current drive cycle), Pending, Confirmed, Warning indicator requested
============================
Engine #2Engine #2
DTCs: 1
----------------------------
P0303(00) [0x030300]
Cylinder 3 - misfire detected
No. 3 Cylinder Misfire
Status: Test failed (current drive cycle), Pending, Confirmed, Warning indicator requested
============================
ABSABS
DTCs: 1
----------------------------
U0401(68) [0xC40168]
Invalid data received - engine control module (ECM)
Status: Test failed, Test failed (current drive cycle), Pending, Confirmed, Test failed since last DTC clear
============================
SRS
No DTC found.
============================
EPSEPS
DTCs: 1
----------------------------
U0416(68) [0xC41668]
Invalid data received - vehicle dynamics control module
Status: Test failed (current drive cycle), Pending, Confirmed

Again, I took my vehicle back to the same dealer and they stated that the head gasket needs to be replaced and cost $3,850. At this point, I will not authorize anything else. I'm at a loss why so many things suddenly went wrong.

Has this happened with anyone else?

 

I had a blown head gasket on 2018 accord 1.5t w/60k miles.
Couldn't believe it.
I replaced it myself and the leak was very minor and it did not contaminate the oil (which is critical for how quickly it needs to be fixed).
If the dealer did a comperssion or leak-down test on cylinder 3 and found the blown gasket, make sure you get the results of these tests.
Dealers are not often honest and skimp on diagnostics.
If you feel you can't trust the diag, and feel ok w/using the car for a day or two as is, do the following to confirm a slightly blown head gasket. (A significantly blown head gasket will be pretty obvious w/other signs.)
Check your coolant level in that well-hidden resevoir just behind the windshield fluid fill cap.
Refill to proper line min/max depending on engine temperature.
Mark the level with a piece of tape and/or marker when the engine is stone-cold ambient.
You have to be precise marking the level so you can see if it's dropping easily.
Drive the car and check the coolant level when it's stone-cold ambient.
If the level has dropped at all, you most likely have the blown head gasket (barring any other coolant leaks).
Also, if the fuel injectors have never been replaced, they may need to be replaced.
I had misfire on cyl#1 which was intermittent at first, then became much more frequent as the gasket leak worsened.
I changed the head gasket (a truly tough DIY job), started up the car, still had misfire on cyl#1.
Changed the fuel injectors and it's been running like new now for 6 months.
Of course, I'm waiting for head gasket and fuel injectors to fail again.
Honda screwed up the design of this 1.5t in that it's too fragile for longevity but it does get great gas mileage between catastrophic failures.
Best of luck to you.

 

Hi Chris60,
Thanks for the feedback. I got my car back from the dealership and reset the CPU on site (detach battery terminals and touch together to clear capacitors). Once that was done, my car started up and drove it home without issue. I haven't done any heavy acceleration testing yet as I want to confirm the actual issue. I'll follow your suggestion and get the diagnostic test results from the dealership. I also spoke to a few auto shops about repairing and one suggested that if the head gasket is truly blown, it may be cheaper to buy a new engine with less miles and a warranty. Still weighing options.

BTW, do you know if a 2.0 will fit in a 1.5 engine cavity?

 

Ha ha, I was trying to do the same thing - replace 1.5t w/a 2.0t.
Answer I got was no since many systems in the car would have to be replaced . . . not economical.
2.0 or 1.5 engines new are about $7k i was told by dealer.
You can probably find a private shop to replace the head gasket for about $2k all in.
If you live in NJ, bcautosolutions@gmail can help you out.
He's the guy who posts utube vids as Hondamobilemechanic.
Good guy to chat with if you can get thru to him.

BTW, my 1.5t problems started about 3 months before it became obvious that I had a problem.
It was a cold evening in sept and i jump in, start the car, and it's running a little rough, then the xmass tree of warnings started.
I was an hour away from home and the car ran completely normal once it warmed up. All the warnings stayed on though.
I cleared them the next morning using an odb2 reader figuring it was a computer glitch due to condensation or some such.
No further issues except a slight rough idle at cold start which disappeared once warmed up.
Warnings came back about december, i took it to dealer for diag.
i was expecting them to say the p0301 was due to fuel injector.
But they did a really crappy job of diag and stopped as soon as they saw the coolant resevoir empty.
Mind you, i didn't even know where that resevoir was until they showed me.
I would check coolant level at the rad cap when cold - was never low.