T56 swap - using A4 trans temp gauge as engine oil temp
01-20-2013, 04:42 PM
#1
T56 swap - using A4 trans temp gauge as engine oil temp
Moderators: Please sticky this for posterity...
When I did my T56 swap in my 2004 Silverado (RIP my friend
), I wired up and used the transmission temp gauge as an engine oil temp gauge. I have since been asked several times how to do this and I figured I should post it for everyone to find.
So, procedure:
You will need to purchase a standard LS1 type coolant temp sensor (like is in the cylinder had) and connector (both can be purchased at the dealership).
My GM service manuals (the real things) confirm that the temp-vs-resistance of the LS1 coolant and automatic trans temp sensors are exactly the same. So the LS1 coolant temp sensor will read accurately.
Locating the trans temp wires:
You will find the trans temp gauge wires in the big 20pin round connector.
- pin M (shows as gray in my book) is the low reference side
- pin L (shows as yellow/black in my book) is the signal side
Wiring Connections:
- pin M to the block/low ref on the new sensor
- pin L to the yellow/signal on the new sensor
To mount the sensor:
- With factory oil cooler, remove the oil cooler block on the drivers side. Drill and tap the oil block to mount the sensor. I choose to mount my sensors on the "cold side" (post cooler/oil entering block) as this is the actual temperature being fed to the engine. Others like the hot side. It's personal preference and won't really change anything.
- Without a factory oil cooler, find the oil cooler bypass block on the drivers side of the block. The bypass block has a boss for installing a sensor or tapping for a feed port. Drill and tap this boss.
- Some people just mount their sensor in the oil pan below the oil level. Their argument is that this is the hottest the oil can possibly be. Again, personal preference.
Some things I learned/experienced:
You will need to leave the Automatic tune in the vehicle, otherwise the "trans" temp sensor will be disabled. The downside (that I found) of this is you MUST have the clutch depressed when you key on, otherwise the computer sees the trans out of "park" and won't crank. Even if you push the clutch in (which would tell the computer the trans is in "park"), it didn't always want to crank (can't explain why....seems odd but I didn't have my truck long enough after the swap to investigate the issue further). I know this was not from a faulty wiring connection or other such issue. When this happened I always had to key off and key back on to crank. It's an inconvenience at first but you get used to it very quickly. If you install the manual trans tune this issue is solved, however you loose the "trans temp" operation.
Other than that, everything else works fine (cruise works fine, no MIL codes, etc.) and the new "engine oil temp" gauge is quite responsive and accurate.
Enjoy!
When I did my T56 swap in my 2004 Silverado (RIP my friend
), I wired up and used the transmission temp gauge as an engine oil temp gauge. I have since been asked several times how to do this and I figured I should post it for everyone to find.So, procedure:
You will need to purchase a standard LS1 type coolant temp sensor (like is in the cylinder had) and connector (both can be purchased at the dealership).
My GM service manuals (the real things) confirm that the temp-vs-resistance of the LS1 coolant and automatic trans temp sensors are exactly the same. So the LS1 coolant temp sensor will read accurately.
Locating the trans temp wires:
You will find the trans temp gauge wires in the big 20pin round connector.
- pin M (shows as gray in my book) is the low reference side
- pin L (shows as yellow/black in my book) is the signal side
Wiring Connections:
- pin M to the block/low ref on the new sensor
- pin L to the yellow/signal on the new sensor
To mount the sensor:
- With factory oil cooler, remove the oil cooler block on the drivers side. Drill and tap the oil block to mount the sensor. I choose to mount my sensors on the "cold side" (post cooler/oil entering block) as this is the actual temperature being fed to the engine. Others like the hot side. It's personal preference and won't really change anything.
- Without a factory oil cooler, find the oil cooler bypass block on the drivers side of the block. The bypass block has a boss for installing a sensor or tapping for a feed port. Drill and tap this boss.
- Some people just mount their sensor in the oil pan below the oil level. Their argument is that this is the hottest the oil can possibly be. Again, personal preference.
Some things I learned/experienced:
You will need to leave the Automatic tune in the vehicle, otherwise the "trans" temp sensor will be disabled. The downside (that I found) of this is you MUST have the clutch depressed when you key on, otherwise the computer sees the trans out of "park" and won't crank. Even if you push the clutch in (which would tell the computer the trans is in "park"), it didn't always want to crank (can't explain why....seems odd but I didn't have my truck long enough after the swap to investigate the issue further). I know this was not from a faulty wiring connection or other such issue. When this happened I always had to key off and key back on to crank. It's an inconvenience at first but you get used to it very quickly. If you install the manual trans tune this issue is solved, however you loose the "trans temp" operation.
Other than that, everything else works fine (cruise works fine, no MIL codes, etc.) and the new "engine oil temp" gauge is quite responsive and accurate.
Enjoy!
Last edited by 2001CamaroGuy; 01-20-2013 at 05:04 PM.
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