Pwr Locks, Pwr Mirrors, Pwr Liftgate, Fuel Filler Door, Dvr Pos Mem All Quit Working

[KC07MDX]

I have an 07 MDX Technology/Entertainment

Here are my symptoms and the order in which they began to the best of my recolection:

Power liftgate release button on the driver door became inoperable. Light went out on the button and it did nothing when it was pushed. The only way to get the power liftgate to operate automatically was to use the button on the key fob. At this point you could still open it manual from the back of the vehicle as well. Wasn't too worried about it so drove it like this for a few months.

Then the following happened all at once. When I get out of the vehicle and lock it with the key fob all the doors will lock. It used to be if I pushed the lock button on the key fob a second time I would hear a "beep" but there is no longer a "beep". Also, when I try to unlock the vehicle with the key fob the driver door will unlock. It used to be if I pushed the unlock button on the key fob a second time the rest of the doors (including the liftgate) would unlock; however, now the drivers door trys to unlock again but the there is no sound from the other doors (including the liftgate). I can unlock the doors from the inside manually; however, it is not possible to manually unlock the liftgate so it can no longer be opened because it remains locked.

The next thing I noticed was the lock/unlock buttons on both the driver and passenger doors do abosolutely nothing. Same thing with the drivers position memory buttons on the drivers door (driver 1 and driver 2); however, the vehicle does seem to recongize my key fob because it still says "welcome driver 2" on the info screen when I start the car, but my seat does not position itself automatically. The power mirrors are also inoperable. The other item that does not work is the fuel filler door release next to the power liftgate button on the driver door; thus, the only was to put gas in the car is to use the manual release above the rear fuse box (this is a pain in the).

I read in another post that if one of the side view mirror acuators goes out it can shut down many of these systems. A number of months ago my wife had a mishap that damaged the passenger side view mirror. The mirror still operated for a number of months, but the actuator was damaged some because the mirror jiggle as the car was driven. Since that actuator was damaged anyway I thought I would replace it and see if it fixed the other issues. Unfortunately that did not do the trick, but I do have a solid side view mirror now (no more jiggling).

I was wondering if anyone has any ideas before I take my vehicle to the stealership? I haven't had very good luck with the two here in town. I appreciate any help you can provide.

Thanks

[danny57010]

I would start by checking the fuses

[KC07MDX]

Danny,
Thanks for your reply. You and I are on the same page. I forgot to mention above that I checked all the fuses in all four fuse boxes. The only one I found blown was the rear accessory outlet and I think it has been blown since we purchased the vehicle. Thanks

[Len90]

The only thing that comes to mind is a computer chip that has blown.

[SuperTech]

With that many different symptoms, I'd say there may be a problem with one of the multiplex units. But no way I'd say for sure. That's gonna have to go to a dealer and be diagnosed by someone who's good in advanced electrical problems.

[maliaschwenk]

You and I are on the same page.

[TattooJohnny]

Sounds like the issues I had in my 08 Tech.........you not gonna beleive me but it was the motor for the power mirror.........I had both replaced and no issues since.......For what it worth.........Good Luck!!!

[KC07MDX]

Johnny,
By "motor" do you mean the actuators?
Thanks

[TattooJohnny]

Yea, sorry KC.....I was rushing when I answered that......both actuators were replaced and everything was and has been working fine since.

[KC07MDX]

Everyone, Thanks for the ideas. I talked to one of the service managers at one of the dealers here in town and he echoed Johnny's idea of replacing both mirror actuators. Since I replaced the passenger side yesterday. I picked another one up and replaced the drivers side today (I'm getting pretty good at it). I also disconnected my battery for about an hour and one-half to try and clear any fault codes. Unfortunately this did not do the trick.

Next I jumpered the MCIC socket in the under dash fuse panel and retrieved the B-Can diagnostic codes. There were a number of them and they are as follows:

B1013 PA10
B1015 PA10
B1065 PA11
B1356 PA31
B1358 PA31
B1182 PA50
B1241 PA51
B1812 PA95
B1905 PA96
B2207 PA97
B2208 PA97

With these codes, I'm kind of like the dog that finally caught the car: I don't know what to do with them (I need a list of what they are). Any ideas on what these are would be greatly appreciated.
Thanks

[sigp228]

Originally Posted by KC07MDX

Everyone, Thanks for the ideas. I talked to one of the service managers at one of the dealers here in town and he echoed Johnny's idea of replacing both mirror actuators. Since I replaced the passenger side yesterday. I picked another one up and replaced the drivers side today (I'm getting pretty good at it). I also disconnected my battery for about an hour and one-half to try and clear any fault codes. Unfortunately this did not do the trick.

Next I jumpered the MCIC socket in the under dash fuse panel and retrieved the B-Can diagnostic codes. There were a number of them and they are as follows:

B1013 PA10
B1015 PA10
B1065 PA11
B1356 PA31
B1358 PA31
B1182 PA50
B1241 PA51
B1812 PA95
B1905 PA96
B2207 PA97
B2208 PA97

With these codes, I'm kind of like the dog that finally caught the car: I don't know what to do with them (I need a list of what they are). Any ideas on what these are would be greatly appreciated.
Thanks

First, I have to say, I am not a mechanic or an expert, but I did stay at a holiday inn last night. I do have the 2007 service manual (I bought it for my first MDX) and parsing the manual I found the following:

B1013 PA10--MICU lost communication with the drivers MPCS unit (aslocksw message)
B1015 PA10--MICU lost communication with the drivers MPCS unit (drlocksw message)
B1065 PA11--Relay control module lost communcation with the drivers MPCS unit (drlocksw message)6
B1356 PA31--power tailgate control unit lost comm with drivers MPCS unit (drlocksw Message)
B1358 PA31--power tailgate control unit lost comm with drivers MPCS unit (aslocksw Message)
B1182 PA50--Gauge control module lost communication with drivers MPCS unit (drlocksw message)
B1241 PA51--A problem in the blower motor circuit
B1812 PA95--Power seat control unit lost communication with driver's MPCS unit (memsw message)
B1905 PA96--Immobilizer-keyless control unit lost communcation with the drivers MPCS unit (drlocksw message)
B2207 PA97--Navigation control unit lost communication with with AcuraLink control unit
B2208 PA97--Handsfreelink control unit lost communcation with Acuralink control unit

I am seeing a pattern here with the drivers side MPCS (mulitplexing control system). I think the last two could be something else. I don't think it has to do with the mirrors because TSB 09-047 deals with the following:

SYMPTOM
Either or both of the door mirrors have one or more of
these symptoms:
• After shifting out of R, the power mirror does not
return to its normal position.
• When shifting into R, or adjusting the mirror with its
adjusting switch, the mirror chatters or pulses.
• The DPMS doesn’t recall one or both of the mirror
memory positions.
• The DPMS moves the driver’s seat 1 inch, then
stops.
PROBABLE CAUSE
Faulty door mirror actuator.
CORRECTIVE ACTION
Replace the door mirror actuator(s).

It never mentions problems with the keyfob, locks, etc. Some of those DTC's are related to keyless entry, door lock switches, and the seat. All problems you are describing.

Looking at a wire diagram, it appears the MPCS is connected to no 7 and no 21 fuses as main power (again I am no mechanic) so I would double check all the fuses very carefully as sometimes they blow but the break is so small and there is no black burn to indicate it. Then the question is why did it blow.

Of course it could also be a loose/bad connector with the drivers side MPCS (which is located inside the drivers door behind the trim panel). Check for corrosion. If the plugs have lost on them then water is/has gotten in there (and then I would be worried as to how/why).

Finally, you drvers MPCS might have gone kapooie. Hope this helps.

[KC07MDX]

Great information!!! THANK YOU VERY MUCH. It does appear to be narrowing in on the drivers MPCS unit. As the test procedure states I checked the No.7 and No.21 fuses before beginning the MICS Diagnostic Test Mode 1. If I remember correctly the interior lights went off when I pulled one of those fuses; however, they came back on when I put it back in; thus, I know for sure one of them is fine. It appeared to me the other was fine as well, but I will pull them both again and check their continuity with a multimeter.

I think my next step, if the fuses check out, will be to put the system back into Test Mode 1 and clear the codes. Then I will take the car out of Test Mode 1 and retry the systems that were inoperable (door locks, power tailgate release button, power mirror adjustments, driver position memory, etc.). If they still do not work, which I anticipate they won't, I will go back into Test Mode 1 and see what codes are then stored. My thinking is some of the codes currently in memory may be from temporary faults or old issues that have been corrected. This way I should be able to find out the current codes.

I would anticipate seeing a number of the codes I listed before. If this is the case, I am planning to clear the codes and put the system into Test Mode 2. Then perform the list of tests for the Driver's MPCS Unit (i.e. Power window master switches, Driver's door key cylinder switch, Driver's door lock switch, Driver's door lock knob switch, Left rear door lock knob switch, Driver position memory switches, Left rear power window switch, Fuel fill door opener switch). I may also perform the tests for the MICU (i.e. Driver's door swiitch, Front passenger's door switch, Left rear door switch, Right rear door switch, Audio security ground when disconnected<--not really sure how to check this one so I might skip it, Mirror select switch, Mirror switch).

It is my hope by doing these procedures I will be able to determine what circuit to investigate to solve my issue.

I'm open to any other suggestions or tips before I begin. It may take me all weekend to get around to this, but I will let you know how it turns out.

Thanks

[sigp228]

no problem, just let us know what you find.

[KC07MDX]

I just put the vehicle back into Test Mode 1 and cleared the codes. The following codes came right after I cleared them:

B1013 PA10--MICU lost communication with the drivers MPCS unit (aslocksw message)
B1015 PA10--MICU lost communication with the drivers MPCS unit (drlocksw message)
B1065 PA11--Relay control module lost communcation with the drivers MPCS unit (drlocksw message)6
B1356 PA31--power tailgate control unit lost comm with drivers MPCS unit (drlocksw Message)
B1358 PA31--power tailgate control unit lost comm with drivers MPCS unit (aslocksw Message)
B1182 PA50--Gauge control module lost communication with drivers MPCS unit (drlocksw message)
B1812 PA95--Power seat control unit lost communication with driver's MPCS unit (memsw message)
B1905 PA96--Immobilizer-keyless control unit lost communcation with the drivers MPCS unit (drlocksw message)

All things seem to point to the drivers MPCS unit.

I did go ahead and put the system into Test Mode 2 and it appeared my side view mirror control circuits are fine (the interior lights blinked when I operated the switches). I got no response from the following buttons:

Power tailgate release (on driver door)
Fuel filler release (on driver door)
Power locks open/close (on driver door)
Power locks open/close (on passenger door)
All three seat memory buttons (driver 1, driver 2, memo) (on driver door)
Flipping the door locks manually on all the doors
Using the key in the drivers door

All four switches that tell whether the doors are open or closed operate correctly. One thing I did notice, when I pushed in the driver door position switch (the one that senses if the door is open or closed) to indicate the door was closed the driver door lock sounded like it was operating.

I assume this all points to the driver MPCS as the culprit. Not really for sure where to go from here. I have an appointment at the dealership Monday. It looks like I might have to use it.

[sigp228]

The manual had an MPCS input test procedure did you do that. I might be able to make a PDF of the pages and send them to you.