Vtm and A/F codes and P0154

Tiny
DIVIDES
  • MEMBER
  • 2008 ACURA MDX
  • V6
  • 4WD
  • AUTOMATIC
  • 160,000 MILES
Have this vehicle listed above with sh-awd and check engine lights on. First it had 77-1, p0154 and rocker arm code, can't remember it, I replaced the vvt solenoid and that took care of the last code. The other 2 are still there p1054 a/f and the 77-1, are these by any means related? I looked up 77-1 and it said functional abnormalities of fuel emission or automatic transmission, what? Lol
Tuesday, July 27th, 2021 AT 6:51 PM

9 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,097 POSTS
Hi,

I went through the manual for your vehicle, and the P1054 isn't shown. I know normally that is an air/fuel code, but it isn't identified as relevant for this vehicle. Please confirm that code for me.

As far as the 77-1, that is a communication error with the PCM. Interestingly, one of the components it could be related to is the PG MFI (fuel injection) which could cause an Air/Fuel mixture. However, according to the test procedure, it could also be related to the AWD control unit. See pic 1 below

The manual indicates if there is a code related to the PG MFI system, to start diagnosing with the codes stored. Since I don't have a listing for 1054, I'm at a standstill. So, please confirm that is the code you have.

Let me know.

Joe

See pic below.
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Tuesday, July 27th, 2021 AT 9:19 PM
Tiny
DIVIDES
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Where is the sh-awd unit?
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Wednesday, July 28th, 2021 AT 6:57 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,097 POSTS
The first pic you have above is specific to the heated o2 sensor. The second is what I was finding when I tried to research it.

Since you have a code for the oxygen sensor and an indication of an emissions issue, that is where I would start. However, I'll let you make that call.

As far as the SH-AWD unit, it is in the left quarter panel of the vehicle. I attached a pic of the location below. Also, note it has its own relay near it as well. You may want to check that as well.

Here is a link that explains how to test a relay. Also, make sure the connections are in good condition, tight, and no corrosion.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

As far as the unit is concerned, have you replaced any rear axles recently? Also, is the differential fluid full? Are the tires all the same size?

Let me know.

Joe

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Wednesday, July 28th, 2021 AT 7:11 PM
Tiny
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I bought it like it is from the auction and drove it home. No did not change any axles. Tires I have not checked. I am aware of tire sizes causing issues, I will check. Differential I have not checked.I will change the oxygen sensor first and see, it's easy to replace. I have had Acuras in the past with o2 codes that drove me crazy, hard codes and you cannot delete. Problem is that the sh-awd light comes on just by starting the car and leaving it running, while cleaning it, so just strange.
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Wednesday, July 28th, 2021 AT 7:36 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

I noticed on your scanner that it indicated it's a permanent code.

I just realized something. In your first post, you mentioned a p0154. Later in the post, you mentioned a P1054. By any chance did you transpose the numbers? That would explain why I'm not finding the 1054.

I am attaching the diagnostics for a P0154. I hope this helps. Note: Starting at pic 5 is advanced diagnostic information.

Let me know if that number got transposed.

Take care,

Joe

See pics below.
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Wednesday, July 28th, 2021 AT 9:16 PM
Tiny
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Ya sorry, it's p0154.
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Thursday, July 29th, 2021 AT 6:59 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

No problem. I just caught that last night and wanted to confirm. It made sense to me as to why I couldn't identify the code for this vehicle.

The diagnostics I provided should align with that code. Let me know what you find or if you have other questions.

Take care,

Joe
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Thursday, July 29th, 2021 AT 1:21 PM
Tiny
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Changed the a/f both codes are gone for now. Thanks for your help.
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Thursday, July 29th, 2021 AT 1:39 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Hi,

Thanks for the update and I'm glad to hear the codes are gone. Hopefully, that will take care of the problems.

You take good care of yourself and feel free to come back anytime in the future. You're always welcome here.

Joe
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Thursday, July 29th, 2021 AT 7:25 PM

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