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It is never late to try it out:

The car will complete 7 years this week. The Odometer at 197,000 Km will soon be reaching the 200k milestone in coming months. On my 2013 VDi variant, I didn’t miss most of the creature comforts till now or should I say I just cared too less about having such features in my car. But then, suddenly the itch starts and I did it. No, I didn’t book another car because I got bored of this but I installed the Steering Mounted Audio controls on my 1st Generation (Type 1) Ertiga VDi and that makes me happy! So here’s a thread that I have penned capturing almost every possible detail that resulted in executing this not-so-easy DIY.

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Step 1- Homework:

There was a lot of thought process and time that went into this. The more I thought it was simple, a lot started to reveal and it made me realize that a detailed and a careful assessment was absolutely necessary to first ensure that this DIY was possible at all. I spent hours on Boodmo, glancing through the images of couple of steering wheels of other Maruti cars, including Ertiga to figure out the design, construction and other elements like wiring inside and the dimensions. There were many moments where I thought I should abandon (the thought) and forget about it but somehow after further studying the images and watching few videos on YouTube, I started to convince myself that this seemed tryable.

Mind you, there were a lot of installers from NCR region who have videos on YouTube where they have successfully installed steering mounted controls for almost all the models of Maruti. Plethora of videos are evidence to it. But one thing became very clear when I fully watched one of the videos where one such installer reiterates the fact that they can only install the steering controls on all Maruti cars that have Airbags and they don’t do it for cars without Airbags. Of course, the videos themselves end abruptly with not much information. Also, it made sense when they said that Airbags are must because my 2013 VDi then never had Airbag and that means there was no “Contact Coil”.

I then stumbled upon a video where a gentleman replaces a bad contact coil in the first Generation Ertiga. I would watch that in slow-motion and even take screenshots to understand the similarities and differences between a Steering of the Ertiga with no Airbags (mine) and the one with the Airbags (in the video).

https://www.youtube.com/watch?v=94LtNiLgfGk&t=336s

• The Wiring for the Horn:
  I noticed that the wiring for the horn circuit was straightforward as my car and that a wire’s presence inside the steering gave the right hints.
  
  
• Signal wires for the buttons and illumination:
  The presence of a 6 pin coupler inside the steering wheel was to understand the number of wires that were doing the job – For the Horn as well as the Audio control buttons.
  
  Since this video had an Ertiga with just Stereo controls (No BT), the 6 pin coupler had just 5 wires and I tried to isolate few wires one by one by assigning them their functions by looking at the wiring diagram that Leoshashi had helped with me for the first Gen Ertiga. In the diagram, it was clear that there were just 2 wires that originated from the steering buttons and directly connected to the back of the OE Head Unit on Pin 19 and 20.
  
  
• Couplers/Connectors:
  Although I learnt that the steering wheel with the Audio and Bluetooth buttons will have coupler as part of it, I was particularly wondering about availability of such a coupler that I would need on the contact coil below the steering to interface the signal and other wires. This is the screengrab that shows the coupler that I would need.

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Step 2: Understanding the current steering wheel set-up and its components:

Having removed the steering wheel of my car quite a few times in the past, I removed it once more, this time beyond just the wheel to understand various underlying components on job that aided in the following functions:

• Horn
• Indicator cancel function

The construction of the steering wheel for a non-Airbag variant is really simple. A horn pad on top below which there is a mount/frame on which the horn pad with the Suzuki logo snaps onto:





Once you pull out the steering wheel, you will notice another important element which is the indicator cancel cam. You can also notice some free space above the cancel cam which hints that most parts are shared between variants to accommodate additional parts.



The indicator cancel cam also has the coupler for horn(in blue) as part of it.



The cancel cam is held onto the steering column by 3 locks that you expand and pull it out.



Just below the cancel cam, as part of the steering column is where you will notice the mechanism for the indicator stalk (cancel) function.



The circled area on the right hand side of the image has the plastic notch that protrudes out upon turning the indicator stalk in either direction (left or right). When the indicator is not engaged/off, the notch disappears inside as you can notice the left hand side of the image.



A close look at the cancel cam. The marked portions help to cancel the indicator after the wheel is turned in the opposite direction to that of what the indicator is pointing to.



Horn and its working:

One of the other basic function for a VDi steering wheel is the horn. The mechanism is quite simple. The Horn switch when pressed completes the ground and you hear that honk. The wire inside the steering is connected to the metal of the steering body. The steering body has a metal ring underneath that is constantly “in contact” with a spoke on the cancel cam. So whichever direction you turn the steering wheel, this contact is always established and your horn will function whenever you press the horn pad.

The below image is a combination of the steering wheel component depicting the Horn Pad, the metal ring underneath the steering and the spoke that is part of the cancel cam.

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The Contact Coil:

When I looked at the parts catalogue for the first gen Ertiga, I learnt that all the variants share the same steering column and column covers. That means, the only difference was the presence of a contact coil in airbag equipped variants or the absence of the cancel cam in non-airbag variants. A contact coil was the first part that was ordered online via Boodmo which arrived in under 3 days.

The below images of contact coil have highlighted portions that show the sockets on the contact coil – one that shall remain inside the steering wheel facing the driver and the other socket below the steering wheel towards footwell area



The contact coil also complements the function of cancel cam as explained earlier and this is exactly how:



6 PIN JST Connector:
This was perhaps a very crucial step for a clean installation. I really had to find a coupler that could slide into the socket of the contact coil below the steering wheel side.



I needed the above coupler to accomplish a clean DIY.

I studied more about the type of couplers, their construction and the fact that most couplers come with universal standards and spacing between their pins. I measured the distance between the pins on the socket of the contact coil. It was 2.5mm between each Pins. Then I found a 2.54mm JST 6 Pin connector online from www.robu.in. Believe me, till it arrived, I was still unsure whether this DIY will proceed further at all and whether the connector itself would be a right fit. The connector arrived in 2 days and the first thing I did was to slide the connector into the socket. That was the moment of excitement as the connector was a perfect fit and easily slid into the socket. To ensure that I had not bent any pins on the contact coil by accidentally forcing the connector in, I even pulled the connector out and slid it again. To ensure the connectivity between 2 ends of the contact coil (Inside to outside) was working, I tested using the multimeter for each of the 6 pins.

The JST 2.54mm 6 Pin Connector:



How the connector was a perfect fit into the socket



Checking the fitment of the contact coil on steering column:

I now had the contact coil and a coupler that fit precisely into the socket. So the ray of hope was getting stronger. The next step was to check the fitment of the contact coil onto the steering column. This was absolutely easy. I could simply place the contact coil onto the steering column and gently press at 3 places and it locked itself securely onto the column.



I then put the steering column cover on top only to check if it fits without hindrance and it very well did. I didn’t attempt to fit the lower half of the column cover was I was sure that would fit too.

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Choosing the right Horn pad:

For the airbag equipped steering, the horn pad also has the airbag inflator module as part of it. That means, it is an expensive affair to order a horn pad of an airbag equipped steering merely to make the steering buttons function. I had already decided that, by taking the fabrication and aluminum welding route, I would somehow customize a horn pad clamp to place the horn pad onto it. So I ordered the horn pad in BLACK of the lower variant Celerio without much wait.

Choosing the right steering:

At least with the information that I had gathered, I was sure that the Ertiga and Celerio had similar steering wheels. Also, in 2013 till around 2016 IIRC, the Ertiga Z variants had only stereo controls on the steering and BT/calling function buttons were missing. Post 2016 or so, Ertiga started to have both Stereo and BT controls on the steering. So I placed an order for a BEIGE steering wheel for 2016 model through Boodmo. The part never arrived and it was an endless wait for 2 weeks when I decided to change my plans. I kept this order open and placed a parallel order, this time for the BLACK steering wheel of the Celerio Z variants that comes with both stereo and BT controls. I was perhaps OK to experiment between black and beige only to see things work.

The steering wheel of the Celerio arrived In 10 days. The following image helps you understand the major difference between the steering wheels, especially on what is below the horn pad. As you can notice, the major difference is indeed the frame to mount the horn pad in the new steering which is absent here as the horn pad for this steering comes with airbag module.

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Checking if the steering wheel fits well:

This was a crucial step too and if this failed, the DIY would probably be abandoned midway. I was confident since I had researched so much that it will fit and I wasn’t disappointed. The steering was a precise fit on top of the contact coil (you can see the coupler in the top center), from every angle and in every direction:





Interestingly, the OE steering without airbags has some extra construction below it which otherwise is occupied by a contact coil in higher variants:

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Fitment of horn pad onto the steering wheel:

The horn pad mount/frame is made of metal and has 4 contact points on top. When the horn pad is pressed, the contact points touch the main body of this frame which is actually bolted onto the chassis of the steering wheel which again is connected to the steering column. Hence pressing the horn pad completes the circuit by grounding the negative and the honk is heard. Here is an image that shows the horn pad from my current steering from various angles. As you can see, it has 4 legs that are directly in contact with the steering wheel skeleton metal where it is bolted to.



The Celerio horn pad was tested onto the mount of my car and it was a direct fit without much ado:



While I was more than sure that the horn pad mounted onto the frame is anyway going to be an odd fit onto the new steering, I simply placed it over the steering wheel. Realised that there is a lot of “Height reduction” that would be required.





Also, in its present state, the horn pad mount/frame’s position of legs were nowhere closer to any of the existing holes in the steering wheel skeleton:



Fabricate the frame or try out something?

While I was ready to fabricate the base of this mounting frame keeping the top same, I really wanted to try once to bend the legs of the mount and see if I can somehow bring the mount to the desired position and height. There were 4 holes on the steering wheel that I could leverage to fit the mount but I could do so only if I bent the legs in different directions and angles. I first bent the legs on the upper side and secured them with screws so it gives me a good grip to then bend the other 2 legs. After a couple of attempts, I could manage to bend the remaining 2 and secure them with bolt & nut for one of them as there was no thread for holes in the bottom while the other hole was secured along with the screw that was holding the BT buttons.

To align the horn pad at the right position, I carefully bended all the 4 legs to get that desired positioning. This is how twisty the mount looked after locking it in its final position.



Mind you, the material is not delicate and required quite some effort to bend using a proper cutting plier and this had to be done by securing it on the steering wheel only and not independently on a vice. The mount in this position felt very much secure and strong as I removed and refitted the horn pad multiple times after this. The below image shows the final fitment of the horn pad mount/frame in the desired position. Circled areas represent where and how it was secured:



The horn pad fitted onto the steering:



Finally, a comparison between the 2 steering wheels, where I removed the horn pad mount/frame from the OE steering and fitted that onto the new steering.

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Wiring of switches for signals and illumination:

After tasting success with the cosmetics, it was time to test the functions. Soon after the steering wheel arrived, due to the fact that this wheel also came with BT control buttons along with stereo control, it was important to know about the wiring, especially for signaling the stereo and illumination. D-Bhpian audioholic was helpful enough to share some details regarding the pin out diagram of the Celerio steering wheel. However, when I performed the resistance test between the pins on the steering wheel socket to test the resistance values, I found partial success because only one of the buttons (stereo) passed the resistance test on the multimeter.

This is the socket on the steering wheel that would connect to the contact coil to interface between what is inside the steering wheel to the outside of the steering wheel.



I attempted to open one of the switches to understand the wiring, especially what each color of the wire represents and it became clear that both the switches use a pair of wires for powering the LED for illumination and one common wire shared between both BT and Stereo buttons.



With much clarity now, I plotted a wiring diagram on a piece of paper labelling every color of those 6 wires against the functions they performed. The below circuit diagram represents the overall wiring of the steering control buttons, including illumination, signal to the Head unit for BT and Stereo and Horn. In short, this represents the entire circuit involved in this DIY:


(The colors used to depict the wiring are actual colors of the wiring system)

After this, I tested the pins for resistance check and it displayed/changed values flawlessly. In the above diagram, pins labelled 2,3 and 4 are for steering control buttons.:

• Pin No 2 – Bluetooth and Phone Controls
• Pin No 3 – Common/Ground
• Pin No 4 – Stereo Controls
• Resistance between Pin 2 and 3 was checked for functioning of BT and Phone control buttons
• Resistance between Pin 4 and 3 was checked for functioning of Stereo control buttons

Essentially, when none of the switches are pressed on both the stereo or BT buttons, the resistance values are above 5000 Ohms. Pressing any of the switches would display resistance value that is less than 1000 but would remain distinct for each button every time you pressed them. The stock head unit would read these resistance values and performed a preconfigured function.

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Wiring the interface:

The new steering had to be wired and connected to the right sources/destinations and they included:

• Horn Ground
• Power and Ground source for illumination
• Stereo control buttons to head unit
• Bluetooth control buttons to head unit

The coupler as part of the new steering had 6 wires, each in distinct colors. Following diagram depicts how each of these 6 wires are connected to different sources/destinations.



Extending and tagging of the wires:

While the coupler inside the steering had set of color codes for the wires, the color of wires on the JST connector on the other side of the contact coil were different. I had to hence keep this in mind, especially the difference in colors and draw it on a piece of paper how various colored wires would interface with each other and where each of these will connect to.

The set of wires originating from the JST connector that has to connect to different sources – Head Unit, Horn, Illumination etc.



To begin with, the horn wire was connected to the horn pad mount:



Further, the length of the wires on the JST connector had to be extended since it was less than a foot long. The extension would enable the wires to reach their sources/destinations. Skinning the ends, twisting, soldering and then insulating them with heat shrink tubes was the method adopted. The remaining 5 wires were extended. I also ensured to secure these wires properly, by using flexible nylon sleeves.







After extending all the wires, securing and segregating signal and illumination wires seperately:



Tagged the end of these wires according to their functions so there was no confusion while completing the final set-up when I get to the car:

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Testing steering mounted buttons with the right Head Unit:

This was the last step before calling this DIY a success. The wiring was ready, tagged and it was time to check if pressing the buttons made the head unit read the resistances and perform the actions accordingly. I had 2 Head Units at my disposal:

• Stock Head Unit from Nippon
• Aftermarket Head Unit – Kenwood U5130BT

Limitations of the stock head unit:

I had to deal with few unknowns at this stage. My stock unit had the Maruti Standard 20 Pin socket at the back where Pin 19 was for Stereo control and Pin 20 was for Common/Ground. Apparently, in the OE coupler that connects to the back of the Head unit, both the pins (19 and 20) were blanked out since my car never had steering control function. I wasn’t sure if I could try and if this feature would be disabled inside the system although the Pins 19 and 20 on the Head Unit were very much present and were only missing from the female coupler of the audio harness. Further, absence of BT in my Head unit meant I would still not be able to test the functioning of the BT/Call control buttons too.

Limitations of the aftermarket head unit:

The installation manual for the aftermarket head unit from Kenwood had a cable marked for steering control. However, it also referred that it would work only if I had the steering wheel interface adapter. All the latest head units from Kenwood-JVC today do not require any interface adapter as clearly stated on their website. Mine was purchased in 2014.



Testing with the head unit of Celerio for both stereo and BT control:

D-Bhpian Audioholic had sometime back upgraded his Celerio’s stock music system to an aftermarket one and he casually asked me to test the functions by using his stock system. We managed to meet and I collected the system and reached home. I now had both the parts from the Celerio - The steering and the Head unit. The wiring was all ready and tagged to be tested. Illumination was not important at this stage as long as the head unit responded to the steering buttons.

To be on the safer side, I also asked him to share with me the wiring diagram for the Celerio which he gladly did by sending images from the hard copy of the workshop manual.



The workshop manual says to test the resistance of stereo control buttons I need to check resistance between pins 3 and 4. It also mentions that to test the resistance of BT control buttons I need to check resistance between pins 1 and 4. However, since I had opened the switches and traced every wire all the way to the coupler, I found something was amiss in the workshop manual. By the above images, the common pin for both the buttons was 4 while 3 was for stereo buttons and 1 was for BT buttons. But in reality, with no alternation to the wiring or any rearrangement of the pins on the coupler, it was clear that:

• Pin 2 was for BT control (instead of 1 referred in the service manual)
• Pin 4 was for stereo control (instead of 3 referred in the service manual)
• The common pin for both these buttons was Pin no 3 (instead of Pin 4 referred in the workshop manual)

Opening up the switches earlier, drawing them on a piece of paper and tracing them till the coupler helped a lot to resolve this mystery and it was time to perform the final test.

And it was successful:

My car stereo’s OE coupler had no pins on location 8 (Stereo), 19 (BT) and 20 (Common). I couldn’t find compatible female Pins that I could insert into the coupler and test. However, since I was merely testing, I skinned the signal wires from my wiring harness from the contact coil and inserted carefully into the coupler and slid the coupler to the back of the Celerio’s Head Unit. The Unit powered on after I pressed the PWR button and then I first pressed the Volume-up button on the steering and the MOMENT OF JOY – The damn thing responded!!!!!!!

I tested all the buttons on the stereo control module and they responded too. I then paired by phone with the head unit and asked my Dad to give me a ring and I received and hung up the call using the BT Buttons on the steering. Overall, every button responded absolutely well and I was super happy that the project found a success finally after a lot of efforts at every stage over the past 3-4 weeks.

Buttons worked on OE Stereo too:

I then tested the OE stereo that came with my car, this time only with wires for stereo control and they responded too. It means the OE stereo even with no steering control inputs is designed for this alteration and the presence of pins confirmed it too.

What immensely helped here was the opening of the switches earlier, drawing them on a piece of paper and tracing them till the coupler helped a lot to resolve this mystery and it was time to perform the final test.

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Final touch-up:

The rest of tasks were quite straightforward. I tapped the wires from the fog lamp switch as suggested by audioholic though there were wires to tap from that were closer to the ignition key area too. The contact coil had a lock in place (in Blue) that had to be removed after setting the steering to center position.



The cables originating from the contact coil were secured using zip ties and routed properly to their sources/destinations



The contact coil had a cable for airbag inflator module, something that would be of no use in my car and may also rattle when let to hang inside. Knowing that these wires weren’t connected on the other side or exposed, I simply cut them.



The steering was fitted in place (final center positioning was still due) and horn pad fitted on top







Steering Centering:

Basement was perhaps the wrong choice to assess the center position of the steering and hence I ventured out along with the rachet and 17mm socket onto a proper road. I drove the car on straight levelled road for over a kilometer carefully observing the steering position. I realized that it was fitted few notches to the right and that it had to be removed and fixed back 2 notches towards the left to the final position.



For now, I have fitted back my OE stereo, which only has stereo (No BT) and will soon place an order for a touchscreen head unit, and this time with android auto. The new head unit will be a fitting compliment to the buttons too!! This was the image taken after fitting back the OE stereo and while checking how the illuminated set-up looks:



Black and Beige:

I wasn’t sure how everything would gel, especially since my car had all beige interiors. But changing the gear lever knob, the gear lever boot and the steering to black has added some character to an acceptable level I believe:

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Steering mounted audio control buttons in action:

https://youtu.be/yiXcukPl-TA

Other test mules for this DIY:



The all new look, not bad at all:

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How expensive was this DIY?

• Steering wheel Horn pad - Rs.240
• Contact Coil - Rs.1056
• Steering wheel - Rs.2770
• 6 PIN JST Connector - Rs.60

Parts and Tools for the Job:

• Horn Pad
• Contact coil
• Steering wheel
• JST 6 Pin connector
• Socket Spanner (17mm)
• Star screwdriver
• Cutting Plier
• Nose Plier
• Wire stripper
• Heat Shrink tubes
• Soldering Iron
• Digital multimeter (to test continuity, voltage and resistance)
• Cable sleeve
• Cable ties/zip ties
• Few screws, bolt and nuts (secure horn pad frame)
• Wires

Acknowledgements:

My Dad: because he was present all the times holding like a literal torch bearer while I performed this DIY in the parking lot. He would also sit and watch while I experimented with the parts at home. He has been a great companion as a co-passenger and with all my DIYs so far that I realised I had seldom referred him during my earlier posts! He was as excited as I was the moment things worked.

Audioholic for being generous enough to pass me the Head unit so I could test both the Phone and BT buttons due to the the limitations with my Head unit. Also for sharing the wiring diagrams from the Celerio workshop manual. Needless to say, you were getting updates/images at every stage too as I couldn't hold my excitement each time I was crossing a stage with this not so easy DIY .

By the way, remember our discussion on my ownership thread, 4 years back?

Originally Posted by audioholic

Call me when you do this. I will just supervise the whole thing so that you dont go wrong okay? (Now anyone can understand what kind of a joke I just made)

On a serious note, I am curious to see this swap happening. And if it works out I will somehow get the stingray steering controls onto my wagonR.

Leoshashi for sharing the details of the wiring diagram for the Ertiga first generation which is where I could start plotting my plan for this DIY.

Next Plan :
The hunt for a decent budget Head Unit with Android Auto begins. But I have almost made up my mind with the Blaupunkt range and will soon order the same.

Thank you for reading......!!

[Sheel]

Thread moved out from the Assembly Line. Thanks for sharing!

[audioholic]

Having seen all the efforts behind this one, this definitely was not a part swap as I had thought earlier and is a lot more of careful research, procurement of the right stuff and finally some workmanship to mount the horn switch onto the steering. Let me convey my formal appreciation here even though we have already discussed for days Lets try cruise control next. As the previous time, I wish and you dispose