How To: Upgrade your gauge cluster from SR to SR5+

How to ground Pin 36 and clear Low Oil Level warning on 2.7L trucks.

Pin 36 is on the back of the Combination Meter (instrument cluster). It is in the larger of the two connectors which appears on the schematic diagram as C-9. The pin layout and location of Pin 36 in C9 is depicted in the picture below.

First things first. Before unhooking things that are hooked to microprocessors, disconnect the ground on your battery. If you don't do this, then take things apart, plug them back together again, you get weird errors and have to re calibrate things like your traction control. Ask me how I know.

On my 2017 2.7L truck, pins 36, 34 and 30 are not populated in the C9 jack. I had a junk box of old computer cabling parts, and I used the female jack insert from old style D-Sub connectors. I soldered wires from a length of stranded CAT5 cable to them, and put them into the appropriate areas of the C9 plug (it is important to use stranded wires, as solid wires will break eventually with movement).

The concept of grounding Pin 36, and disabling the Low Oil Level warning is simple. Simply assemble a wire with a female jack insert on one end that you will insert into the empty hole for pin 36 in C9, and ground the other end to some metal part of the car body behind the dash. (make sure the part has continuity with the rest of the body. Use the resistance function of your multi-meter to check)

How to make the Right Side steering wheel buttons work:

In a private message I was also asked to describe how to make the right side buttons work. In my 2.7L 2017 truck, the wiring between the combination meter (C9) and the spiral cable assembly (S8) in the steering wheel wasn't present. Pins 30 and 34 on C9 need to be wired to pins 10 and 11 on S8. See the second set of schematics below, note the diagram of the S8 plug.

S8 is on the underside of the steering column. You need to remove the two phillips head screws that hold the plastic cover in place. These screws are exposed if you turn the steering wheel 90 degrees to the right of centered, and 90 degrees from the left of centered. Take out the two screws, remove your keys, gently pry the plastic cover off. S8 is a black jack with 14 pins arranged in two rows. If you find that pins 10 and 11 on S8 are not wired, then you need to wire them. Likewise, you can look at C9 behind the Combination Meter, and find that pins 30 and 34 are not wired.

In my case I did all three wires at once. I cut about 24 inches of stranded CAT 5 (remember use stranded wire for automobile wiring, because these wires are subject to movement and vibration). I identified the three wires I would use. On one end, I soldered female jack ends that were left over from computer D-SUB connector kits (D-SUB are old style computer connectors, DB25, DE9 etc) to the end of each wire. On the other end, I soldered only two female jack ends. On the end that did not get a female jack end, I spliced another 12 inches of wire and put a spade lug on the far end (this will be the ground).

CAT5 has 8 wires in 4 pairs. You are only using 3, leaving 5 extra. Do not strip these extra 5 wires, rather simply fold them back and tape them to the side of the CAT5. Leave them for any additional you may need in the future, or as spares to maintain your work in the future.

There is an existing wire that runs between S8 and C9. Follow that route from the bottom of the steering column, behind the dashboard, to the area behind the Combination Meter. I used small wire ties to secure my new wire in parallel with the existing wire, leaving enough slack on the ends to work and service the equipment and jacks in the future. Clip the excess from your wire ties, using a sharp diagonal cutters the cuts flush against the locking portion of the wire tie. Leaving behind messy wire ties is tacky. Cut them flush so there are no sharps edges when you have to work in that area later on.

You will probably need a small tool to insert the jack ends into the plugs. Note how far they need to go in by laying it along side the plug before you insert it. The tool will be used to force it the rest of the way. There are special tools for this, and with experience you can just use the end of a flat screwdriver. Experience with this includes pushing everything in only half way at the wrong angle, or cutting the wire with the screwdriver blade because you were not careful to push only on the metal end of the jack end. Take your time - avoid getting frustrated.

Make note of the colors of all the wires, and what pins you intend to connect them to. When wiring, draw this out in your notes to keep you straight. As a general rule when learning to work with electronics, the more complex these tasks are for you (or the less experience you have with the particular task), the more elaborate your notes and diagrams should be. Lay everything out on your notes, then build it out just like you drew it out. Double check your work before hooking that ground wire back to the battery.

You asked for pictures, and I'm sorry I just did the work and didn't snap. Here are my notes on prints of the schematic diagram. I recommend printing the pages of the wiring diagram, noting any changes you make, and keeping that with the vehicle records.

 

Do you know how to remove the center plastic that hold wires down I do not want to damage I have this but having a hard time inserting it into pin 36

 

I have a Gauge cluster (56188 Miles)from a 2017 double cab and steering wheel with buttons from a 2017 TRD Off Road for sale if anyone is interested. PM me if you want

 

Im planning on doing this to my 2017 Tacoma 2.7L Access Cab. Found some clusters online and came to terms that I am just gonna have to get a new steering wheel with the controls already one it. Can anyone bring me up to speed on any compatibility issues, wiring issues, etc? That would be greatly appreciated!. Im new to the auto modification game so Im not very savvy with all this. I understand that I will have to ground a wiring to pin 36? Looking at the diagram confuses me lol/ Again if someone can just summarize for my new ass I would greatly appreciate it! Trying to get the parts by this weekend. Tired of driving with some dull analog odometer/cluster!

 

Bumping

 

Still for sale?

 

Hey guys if you are needing mileage correction I can help you out. I have a speedo repair business. Pm me if interested. I can also sell you a complete programmed cluster ready to install as well.

 

I got the low engine oil light off by grounding pin 36 but can’t get steering wheels controls to work i got wire inserts from connectorexperts.com can someone help me I want to finish this mod do I need to ground pin 17 and 18

 

What gauge wire terminal are those?

 

I don't remember precisely - I scavenged them from my junk box of scrap electronics stuff. It was pretty thin, and if I were to guess I'd say 18 or 20.