Prelude:
Volkswagen Vento was launched in 2010 as a Polo with a boot. The car is based on the Polo 6R. The launch editions of the Vento in 2010 and the first half of 2011 had a very mediocre music system. The headunit could only play a single MP3 CD or the FM/AM radio. For a 10 lakh rupee car, the stereo was below average.
My elder brother was one of the first buyers of a Vento (Dec - 2010). Increasingly, it became frustrating for his wife to use the stereo due to the pain involved in burning music CDs for latest audio tracks.
Research:
We started looking at options to upgrade the headunit first. The requirements were simple:
- Should take USB and iPod as media input
- Looks of the facia shouldn't change. No protruding single DIN headunits.
- Minimal changes to wiring and circuitry of the car.
- Additional features like Bluetooth connectivity, A2DP, GPS, etc were welcome.
After intense research, the options were pretty limited. We could use either of the following:
- A stock VW headunit from the Jetta / Passat.
- A stock VW headunit from the upgraded Vento.
- A series of headunits from Blaupunkt specially designed for VW cars. These include the Blaupunkt Philadelphia, New York, etc.
- Some Chinese units like the Caska, Witson, etc.
Team-bhp has some treasure of trove information on a headunit upgrade for the Vento. So referred to these threads:
1)
Thread link.. However bhpian newtonMeter stated that pre-RCD310 units are not a direct upgrade. He also mentioned that it was kind of impossible to upgrade the HU if your car had the RCD300 which my brother's car did.
2)
Thread link.. After further efforts came across bhpian MSP9994's thread on his Polo HU upgrade. This thread has some great information if your stereo doesn't have CAN bus connected wiring harness. Thereafter we were convinced that an RCD510 could be installed in the Vento with a little effort.
And so began our hunt to source the stereo. Getting a headunit from ebay via Chinese sellers was the first option. But, it wasn't straightforward. We realized that the RCD 510 was manufactured by two vendors to VW. One was from Bosch which was made in Portugal while the other was from Delphi and made in China. Googled for the difference and it seems that though the Delphi offers direct USB connectivity, it was relatively poorly built. Additionally, the Indian spec Jetta and the Passat used to get a Bosch unit.
Do note here that even the Bosch unit has multiple part numbers:
- 590 035 190 A (A is not printed on the HU)
- 590 035 190 B (B is printed as a part number)
The unit we bought: Purchase:
Just to try our luck, we walked into a friendly neighborhood accessory shop and lo behold, a Jetta owner had upgraded to a Blaunpunkt unit and had left behind the stock unit. Negotiated the price and requested him to fit the stereo immediately. He was confident that there was no wiring change required although I knew that he would need to change it.
The RCD-510 features a 6.5" touch screen with an in-built 6-CD changer. An SD-card (only upto 32GB) can be taken as an input. Additionally, an MDI kit and a Bluetooth module is plug and play.
Install:
Once the stock RCD-300 was removed, our doubt came to light, the stock connectors in the back wouldn't directly fit on the the RCD510. They were completely different. Not just for the power input and speakers, the antenna connector is different as well. Being a sucker for plug and play, we were sure we wouldn't splice any wires or cut the existing loom.
Wiring connection on the stock pre-2011 Vento:
Wiring connection on the stock pre-2011 Vento:
The PIN input on the RCD510. No luck here:
Logical connection as displayed on the RCD510:
The socket available on the post Sep-2011 Vento (taken from newtonMeter's thread). This is for the RCD310 and features connectivity to the CAN bus as well.
Referred to MSP9994's thread to find a solution and came across bhpian sangtani's post that stated a wiring loom is available to adapt the RCD300 socket to the RCD510. Contacted Sugesh from vagtune and placed an order for the kit. Here are the two parts we ordered:
1) Low line to highline adaptor:
Part link.
2) Antenna adapter:
Part link.
The parts came in later than we expected. However Sugesh was of good help and offered quite a bit of details on the phone. The wiring is priced on the expensive side. If you are a DIY nut, this loom can be built at home by ordering parts if you know the right sources. Additionally, a Blaupunkt Philadelphia 835 has most of these sockets available in the factory shipped box itself. We could have done a little more search and found it somewhere.
Once the package arrived, we got down to do a DIY, opened trim surrounding the HU,
Removed all four torx screws which holds the HU in place:
Removed HU, plugged the wiring into the RCD510 and left CAN wires hanging.
And we ended up with a failure. The headunit wouldn't power on at all. Thought we ended up with a dead unit. Called up the accessory shop guy through whom we had sourced the unit. He asked us to get the car over to his workshop. Drove down and his technician corrected the fault. It was a simple case of a loose socket on the back of the HU.
Now, do remember if you are going to carry out any upgrade to stock VW stereos you'll need a security code to enable it. The security code is bound the chassis number of the car in which the HU was first fitted. This code can be obtained from Volkswagen service centers with a gentle request. You need to provide the chassis number and the HU model, they'll give you a four digit code. If you are buying from ebay, most sellers will give you the code alongwith the stereo. In the Vento, the four digit code is placed on a sticker in the spare wheel well. You need the code each time you unplug the wiring from the back of the stereo.
Then came our worst nightmare, connecting the CAN wires to the BCM. Indian spec Polos and Ventos have the PQ25 module. A good bit of details are available on page 1 & 2 of MSP9994's thread. Sugesh had directed us with a wiring diagram as well. You need a yoga honed body to access the module and unplug it. The technician handling our car made an effort and unplugged the right connector for us. I dived into the footwell several times alongwith my brother to identify which pin numbers we needed to connect to. We had to identify pin #20 and 21 to connect CAN+ and CAN- respectively. But, we encountered something strange.
MSP9994 as well as sangtani had VW Polos which did not come with a climate control. PIN 20 and 21 were already carrying a wire into the BCM in the Vento. Spoke to Sugesh from VAG tune and he confirmed that it is indeed from the climate control module. We were left with no choice but to splice CAN connection wires on the climate control unit
A look at the BCM module holding the connector. You'll notice that this is PQ25:
This is the connector behind the climate control module, and you cannot identify which two wires go into the BCM. So, we had to abort the process and wait.
If you research the internet, you'll notice hundreds of threads stating battery drain issues after upgrade to RCD510 for any previous gen stereos on VW group cars. The main reason for this is:
1) These stereos are not connected to the BCM.
2) If you do not connect to the BCM, the stereo doesn't power off with the ignition, it will remain ON. You have to manually power down the stereo.
Our troubles didn't end there. We drove out of the accessories shop and found out that the CD changer wasn't working. Somethings don't come easily to you, this was one such upgrade. But, we were determined. Called the guy again and he said, he'll arrange for a Passat unit within a week. He did that in two weeks and we got a fully working RCD510 unit directly from a Passat for the same price we initially paid him.
Add on
Next up, riding on the thrill wave, we ordered an MDI kit and Bluetooth module. These are plug and play as we initially thought but it isn't.
These two parts were ordered from ebay and shipped from China. They were delivered at my doorstep in a good 20-22 days since we placed the order.
Removed the HU harness and plugged in the Green (Bluetooth module) and Blue (MDI kit) plugs into the stock harness.
A look at the Bluetooth harness (LHS) MDI kit harness (RHS):
The Bluetooth module has four hanging wires, one Red (goes into power), Brown (goes to ground), a pair of Orange wires that are plugged into the BCM. Similarly, the MDI kit has a Brown wire (ground), and a pair of Orange for the BCM. Since we aren't dead sure about the connections, these are pending confirmation on additional research on how to connect.
Bluetooth microphone that will sit in the cabin light where there is a provision for installing it.
Special note of thanks to bhpian Mariner (my brother) for indulging in the same amount of madness and helping in research and installation while we were at it.