Install Sync3 in 2021 PIU

[paulsobj]

This is the first draft that I hope the next person can refine.

I installed the Sync3 from a 2020 Explorer into a 2021 PIU that had existing Bluetooth (think microphone that was not needed to be added). I needed the Display, APIM, ACM, USB hub, optionally DSP (see notes). You should get the console and console harness and the dash harness. I installed the HVAC as I am installing heated seats and steering wheel. I do not know if you can use the original HVAC, but I think you can. I used the original HVAC bezel and radio controls as the PIU as the dash cut up from the factory. You will need to plan to run your own wires or get the whole body harness from the BCMC to the rear bumper. I did not get a chance to get all the parts that are needed and had to make do with what I had. The junkyard accidently crushed the car before I was done. We will have to do some Forscan mods too. I wish I could know exactly what I did, but there was some trial and error. I will try to get the settings. I know the trouble was related to not using the DSP and using the ACM. I used the ports on the ACM for the D Piller speakers and hooked them to the front door speakers. The civi has a different type of speakers that wont work.

First to go over some of the system.

The PIU system diagram. Notice all the speakers are connected to the ACM that is located under the front lower center console. The antennas have to all run up to the front as well. Mine did not have the FM2 Diversity Antenna. The GPS/satellite is in the fin on top.

Audio Unit Antenna

The audio unit antenna (also called the AM/ FM1/ DAB antenna) is an on-glass antenna, mounted to the left side of the rear window. It receives AM/ FM/ DAB radio waves and sends them through the audio unit antenna amplifier to the ACM via the audio unit antenna coaxial cable (also called the AM/ FM1/ DAB antenna coaxial cable).

ACM in the PIU will look like this, behind the front center console.

Now the 12 speaker system that has the DSP but has the D-pillar speakers still connected to the ACM directly. The CAN lines are networks. The are HS(high speed) CAN1, 2 and 3. Think of that as three separate networks. I ran cables like the stock system, but you can tap into those networks at any point in the harness. They are usually twisted pair and a similar color for each of the networks. They have a few junction blocks like above the woofer taped to the harness (See below)

And finally, the Sync system.

Media hub is the USB ports in the front of the center console.

Item	Description
1	APIM ACM (behind HVAC module, need this)
2	Voice microphone (existing for me)
3	AM/ FM1 antenna amplifier (in the tailgate, existing)
4	Noise filter (existing or not needed)
5	ACM (pass side behind panel, need this)
6	DSP (attached to woofer backside, optional)
7	TCU (inner wheel well, existing)
8	FM2 antenna amplifier (existing or not needed)
9	ANC microphones (existing or not needed)

Some helpful notes on components and how they work here
The ACM takes various inputs such as radio waves and audio signals, conditions, amplifies and converts them to an analog audio signal. This signal can be amplified internally and sent directly to the speakers, or transmitted to a separate amplifier and speaker system

ACM Speaker Output - 4 and 6 Speaker System

The ACM is configured to directly power vehicle speakers. An amplifier in the final stage of the ACM sends an analog AC signal to drive the speakers. Output includes stereo channels. The ACM powers all of the vehicle speakers.

ACM Signal/Speaker Output - 12 and 14 Speaker System

The ACM is configured to directly power some of the vehicle speakers. An amplifier in the final stage of the ACM sends an analog AC signal to drive the speakers. Output includes stereo channels to the front door tweeter and the rear D-pillar speakers.

The ACM outputs audio data over an Automobile Audio Bus (A2B) cable to the DSP. The DSP powers the remaining vehicle speakers. Output includes stereo, center and subwoofer channels.

So you think you are up to the task? Its not too bad, but a lot of wiring labor.

On the parts car.
Seat removal (required for console removal)

1. Move the front seat to the full upward position and forward or rearward to access all of the seat bolts.

1. Depower the SRS.
   Refer to: Supplemental Restraint System (SRS) Depowering (501-20B Supplemental Restraint System, General Procedures). ##I didn’t do this, but that’s what the manual says##
2. Disconnect the front seat harness electrical connector.
   1. Disconnect the electrical connector.
   2. Detach the wiring harness retainer.

1. Remove the front seat bolt covers.

1. Remove the front seat.

Console Removal

You really are getting the harness wires and for the PIU you are missing some connectors. The USB hub is needed. My car had a guardrail blow threw the firewall and the console was in 30 parts, so I got the harness and USB hub without needing to remove anything. You may want to rear HVAC. I upgraded my second row to heated seats. I had existing rear HVAC in the PIU(some don’t).

All vehicles except Police

1. Remove the front seats.
   Refer to: Front Seat (501-10A Front Seats, Removal and Installation).
2. Release the clips and remove the RH floor console side trim panel.

1. Disconnect the RH floor console electrical connectors.

1. Release the clips and remove the LH floor console side trim panel.

1. Disconnect the LH floor console electrical connectors.

1. Remove the bolts, position the console rearward to release the front clips and remove the front floor console

1. Remove the front and rear bolts.

To highlight the conditions I was in, here is a picture of the rear consol area. The car had filled with snow and melted, and froze in the harness in areas (see bottom of picture).

Display removal

1. Release the clips and remove the trim panel.

1. Remove the bolts, release the clips and remove the display.
   • Disconnect the electrical connector.

1. Release the clips and remove the center register trim panel.

1. Release the clips and remove the audio and HVAC control panel.
   1. Disconnect the electrical connectors.

 

[paulsobj]

I missed the plastic part in the middle of the HVAC top shown in the above picture. If you can, get that and the part that the screen has three bolts into. I also intended to get more of the trim where the key button is.

At this point you should have access to the Sync3/APIM that looks like this. I have learned the there is a big difference with the 2020+ APIM when you want to update OS/Maps. They refer to those as “MY20” APIMS.

You will need the cable below and the USB hub its connected to and the USB hub.

Ok, lets move to the rear.

Item	Description
1	APIM ACM
2	Voice microphone
3	AM/ FM1 antenna amplifier
4	Noise filter
5	ACM
6	DSP
7	TCU
8	FM2 antenna amplifier
9	ANC microphones

We are going to get the #5 ACM and the optional #6 DSP.
Removal - Rear Scuff Plate Trim Panel

Removal

NOTE: LH (left hand) shown, RH (right hand) similar. PIU and civi have different panels. If you are swapping 2nd row seats you want these.

1. Release the clips and remove the rear scuff plate trim panel.

Removal - D-Pillar Trim Panel

Removal

NOTE: LH (left hand) shown, RH (right hand) similar.

1. Remove the luggage compartment floor cover.

1. Remove the luggage compartment storage bin.
2. 
3. Remove the liftgate scuff plate trim panel.
   1. Release the liftgate scuff plate trim panel clips.
      Use the General Equipment: Interior Trim Remover
   2. If equipped.
      Disconnect the keyless entry rear antenna electrical connector.

NOTE: Pin-type retainers are located in the rear bin floor of the loadspace armrest trim panel.

Release the clips and pin-type retainers and remove the loadspace armrest trim panel.

Remove the third row seatbelt retractor anchor bolt and position the seatbelt aside.

1. Release the D-pillar trim panel clips.
   
   1. Release the D-pillar trim panel outer lower clip.
   2. Release the D-pillar trim panel outer upper pin-type clip.
   3. Release the D-pillar trim panel front lower clips.

1. NOTICE: The D-pillar trim panel must be positioned downward to allow the upper clips to release correctly. Failure to follow this direction may cause damage to the D-pillar trim panel.

Slide the D-pillar trim panel down, aligning the upper clips to the slots in the sheet metal.

1. Remove the D-pillar trim panel.
   1. Pull outward on the D-pillar trim panel.

1. 1. If equipped.
      Disconnect the D-pillar speaker electrical connector.
2. 1. Feed the third row seatbelt retractor through the opening in the D-pillar trim panel.

Removal - Loadspace Trim Panel

Removal

NOTE: LH (left hand) shown, RH (right hand) similar.

1. Remove the following items:
   1. Remove the rear scuff plate trim panel.
      Refer to: Rear Scuff Plate Trim Panel (501-05 Interior Trim and Ornamentation, Removal and Installation).
   2. Remove the D-pillar trim panel.
      Refer to: D-Pillar Trim Panel (501-05 Interior Trim and Ornamentation, Removal and Installation).

Remove the loadspace trim panel retainer.
Use the General Equipment: Long Nose Pliers

Position the cargo hook bolt covers aside.

Remove the cargo hook bolts and the cargo hooks.

Left hand side

Release the clips and remove the loadspace trim panel.

Right hand side
Remove the loadspace trim panel.

1. 1. Release the loadspace trim panel clips.
2. 1. Disconnect the luggage compartment interior lamp electrical connector.
   2. If equipped.
      Disconnect the power fold seat control switch electrical connector.
   3. If equipped.
      Disconnect the luggage compartment power point electrical connector.

 

[paulsobj]

The ACM is located on the lower passenger side. Confusingly, this is referred to as the Front Audio Control Unit or sometimes ACU in the Ford Electrical manual. It controls the font audio, but is located in the rear. It has one stud on the top with a ground from the main harness and two bolts on the bottom. For some context. This was installed in the front on the PIU behind the floor center console. We are moving it to the rear and with that, the speakers previously were wired to the front, now will go to this or DSP (depends on your choice). The ACM (Passenger side rear) has many wires connecting to the DSP (drivers side rear) and up to the antennas. The mustard coaxial is the GPS/Satellite.

Here is some of the cell antenna wiring. You may not have all of it. My PIU had a TCU and TCU antenna (located to the front of the DSP) that had an antenna in both cars sown below.

Item	Description
1	TCU antenna cable

Both cars did not have the FM2 Diversity antenna that I could tell. See below.

Item	Description
1	Upper FM2 diversity antenna cable
2	FM2 diversity antenna cable in-line connection

Other antennas that you should grab. Basically, take the wires that are installed in the parts car and whatever unit they are installed on. (AM/FM is in the rear glass and on both cars)

Lower AM/ FM1 Antenna Cable Routing - Except Vehicles Equipped With Police Option

Item	Description
1	Lower AM/ FM1 antenna cable
2	AM/ FM1 antenna cable connection to the ACM
3	AM/ FM1 antenna cable in-line connection

Upper AM/ FM1 Antenna Cable Routing

Item	Description
1	Upper AM/ FM1 antenna cable
2	AM/ FM1 antenna cable in-line connection

Lower FM2 Diversity Antenna Cable Routing

Item	Description
1	Lower FM2 diversity antenna cable
2	FM2 diversity antenna cable in-line connection

Upper FM2 Diversity Antenna Cable Routing

Item	Description
1	Upper FM2 diversity antenna cable
2	FM2 diversity antenna cable in-line connection

Front GPS Antenna Cable Routing

Item	Description
1	Front GPS antenna cable
2	Front GPS antenna cable in-line connection

 

[paulsobj]

Center Front GPS Antenna Cable Routing

Item	Description
1	Center front GPS antenna cable
2	Front GPS antenna cable in-line connection
3	Center front GPS antenna cable in-line connection

Center Rear GPS Antenna Cable Routing (Splitter Cable) - Vehicles Equipped With Satellite Radio

Item	Description
1	Center rear GPS antenna cable

Center Rear GPS Antenna Cable Routing (Jumper Cable) - Vehicles Not Equipped With Satellite Radio

Item	Description
1	Center rear GPS antenna cable

Rear GPS Antenna Cable Routing

Item	Description
1	Rear GPS antenna cable
2	Center rear GPS antenna cable in-line connection
3	Rear GPS antenna cable in-line connection

Cellular Antenna Cable Routing

Item	Description
1	Cellular antenna cable
2	Rear GPS antenna cable in-line connection

The DSP is bolted to the back of the woofer. The module to the bottom of the socket is for rear power liftgate and isn’t needed. I think this has the one bolt shown and two on top.

So now you should be regretting staring this project and questioning your life choices like I was. Here is where I started pulling the main harness. I thought it would have a connector at some point, but no. You can pull as much or as little as you think will help. The extent of the systems goes (essentially) the ACM has wires going above and below the tailgate to cross to the driver’s side in the rear and connecting with the shark fin antenna, rear window antenna, DSP, TCU and also has wires going to the APIM (sync3) on both sides below the four doors. Crossing under the front row seats and going through the console. The drivers side going to BCM, and BCMC. Passenger side going up to the dash and connecting to the APIM again. Some may have wires going up the A pillar to the roof console. There are cables going to each door (speaker). This system encompasses so much that you need to pull the whole harness or really understand wiring schematics. I laid out the harness on the floor and bought a Wiring book for about $30 used on eBay. The car I took this from had the 12 speaker system, while the PIU I think just has the two full range front door speakers. So instead of running each speaker to the DSP, I used the D-pillar inputs that were directly on the ACM for my front door speakers. The DSP has outputs for tweeters and woofers, not full range like the PIU (I think the PIU is full range front door speakers?). This is why I did not need the DSP (at this point). I wired the DSP so when I get door panels I can add the higher end speakers easily.

To get the BCMC and BCM and the harness.
Removal - Hood Latch Release Handle

Removal

1. Remove the hood latch release handle.
   1. Rotate the hood latch release handle.
   2. NOTE: Do not remove the retaining clip from the hood latch release handle.

Release the retaining clip.

1. Remove the hood latch release handle.

Removal - Front Scuff Plate Trim Panel

Removal

NOTE: LH (left hand) shown, RH (right hand) similar.

Left hand side

1. Remove the hood latch release handle.
   Refer to: Hood Latch Release Handle (501-14 Handles, Locks, Latches and Entry Systems, Removal and Installation).

All vehicles

1. Remove the front door scuff plate trim panel.
   1. Release the clips.
      Use the General Equipment: Interior Trim Remover
   2. If equipped.
      Disconnect the front door scuff plate trim panel electrical connector.

Removal - B-Pillar Trim Panel

Release the tabs and remove the lower B-pillar trim panel cover.

Remove the lower B-pillar trim panel.

1. Release the lower B-pillar trim panel clips.
2. Feed the front seatbelt retractor and pretensioner through the opening in the lower B-pillar trim panel.

Removal - Body Control Module (BCM)

This is mainly for access to the harness that goes up to the BCMC through the firewall

1. Release the pushpin and remove the drivers side insulation panel.
   • Remove the bolts.
   • Remove the nut.
   • Disconnect the electrical connector.

1. Remove the fuse access cover.

1. Remove the bolts, release the clips and remove the lower steering column trim panel.
   • Release the tabs and position aside the electrical connector and harness.

1. NOTE: The gateway module is mounted to the bottom back side of the BCM.

Remove the nuts and position aside the gateway module. This is hard to reach

1. Disconnect the electrical connectors. Also difficult task
   • Remove the screw and the BCM.

Removal - Body Control Module C (BCMC)

1. Disconnect the battery.
   Release the tabs and remove the BCMC compartment cover.

1. Release the tabs and remove the BCMC access cover.

1. Remove the wire terminal nut and position aside the wire.

1. Fully loosen the BCMC bolts.

1. Release the tabs and remove the BCMC.

The connector to the passenger side on BCMC is the engine harness, the DSP was on the far right. And the ACM was in the middle.



So it’s time to remove the PIU stuff. We will remove the seats, center console, HVAC bezel, vents, dash tray, all the trim on the lower part of the car as you did with the doner car.

I started with the APIM connector and the electrical book pulling the needed wires from the dash harness. I lifted the needed wires and added then to the existing harness. Most of the connectors were existing, but 1-2 console connectors were missing. I used the doner car connectors. The existing connectors usually had empty pin slots where I needed to put wires, but a few places I had to pull out the old wire pins. That was usually in examples where the old wire was the same function, but routed to the wrong place. For example, on the BCM, the power for the ACM pin was already used but ran to the front console. We moved the ACM to the rear. I removed that pin and ran a new wire to the ACM in the back. There is no way to detail the wiring. You should be able to do it with this post and an Electrical book off eBay.

I choose to use the HVAC bezel, key and radio buttons from the PIU. I swapped the HVAC controls.

I got it working before I got all the wiring all tidied up.

I am currently attempting to buy a totaled ST and swap (or investigate how hard) the dash pad, dash screen, steering wheel, front seats, 360 camera…basically the whole interior. This was just phase I.