DTC P026A / Intercooler outlet temp / Aux pump / Velocity AP

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Nechaken

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2016 with Velocity AP Stage 2 (ECU + pulley). I was driving back from the Tetons yesterday and encountered a little power loss while driving over some passes / long hills at ~ 90F ambient (and 6000-7000 feet elevation). No CEL. Plugged in the IID tool and had code P026A (Charge Cooler Efficiency Below Threshold).

Logged some data using IIDtool and "Intercooler outlet air temperature - Bank 1 (˚C)" was pushing 110+ C (or 230 Fahrenheit).

Can anyone confirm that A) that's the right data block for cooled air leaving the intercooler and going into the cylinders and B) that's too hot and probably a sign something is up with the intercooler / auxiliary coolant pump ?
 

alldazed

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FWIW I have a ‘11 rrssc. I have an ultra gauge fitted that monitors supercharger intake temp. On recent warm days about 30c and pretty low altitude- Lake Ontario level the sc intake temp is typically about 70-80 c engine temp below 90c. This is over a pretty good distance > 100miles with one hill and a 3000lb trailer.
My bedtime reading has been the service schedule and it does say to clean the inter cooler fins once a year. I haven’t actually done that yet but it may be a starting point.
 

Nechaken

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Just memorializing some info in case anyone else is looking for it.

Fuse is F28
Relay is R15.

Fuse is good; don't have a way to confirm the relay is good, but coil has ~ 77 ohm resistance, there's voltage at the pins, and pulling the relay triggers a "circuit open" DTC.
 
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16FujiDisco

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Did you clear it and did it return? My first thought is that it was just a product of the immediate conditions; high ambient air temps plus high load demand coupled with the fact that our setup is not the most efficient (intercooler above hot engine). I’m sure the Tetons are a more significant range than the blue ridge/ Appalachians that I drive through on occasion, but I haven’t had any symptoms even with the stage 3 package. @Fuji4 has dug into the aux pump deal probably the most of anyone I’ve read on here, so he may have some good insight
 

Nechaken

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Did you clear it and did it return? My first thought is that it was just a product of the immediate conditions; high ambient air temps plus high load demand coupled with the fact that our setup is not the most efficient (intercooler above hot engine). I’m sure the Tetons are a more significant range than the blue ridge/ Appalachians that I drive through on occasion, but I haven’t had any symptoms even with the stage 3 package. @Fuji4 has dug into the aux pump deal probably the most of anyone I’ve read on here, so he may have some good insight

I cleared it and the code came back several times throughout the drive. (and that included cycling the ignition when stopped). Once I was out of the high heat / high load scenarios it hasn't recurred. I'm thinking aux pump, since data showed that while largely coasting downhill at speed (70+ mph) it still took a pretty long time for outlet temp to drop under 90 C. In any event, I should probably address whatever is causing this before I add the stage 3 pulley.
 
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16FujiDisco

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Check back through the tune thread and there are a couple pages where Fuji4 talks about what he did to upgrade his aux pump and some other theory/tech. Thinking about it, his reason may have been a similar scenario
 

Nechaken

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Check back through the tune thread and there are a couple pages where Fuji4 talks about what he did to upgrade his aux pump and some other theory/tech. Thinking about it, his reason may have been a similar scenario

I think it is definitely not running or running very weakly. I took a mechanics' stethoscope to it and hear basically nothing. Going to borrow a friend's LR4 on Monday to compare.

I went ahead and swapped the relay out - FoMoCo Part V23136-J4-X62 is identical to the JLR 12V 70A relay, with a difference of .2 Ohm on the relay coil (looks to be the same OEM, probably just manufacturing tolerance). Cheaper and available instantly too.

Also paid for a brief topix subscription to figure things out. Fuji4's posts indicated the pre-2016 cars use a 2-wire pump that he could swap out with a larger/higher-volume pump. While the 2016 has a 3-prong connector, only two wires are used. So I'm guessing I could use his same upgraded pump if I wanted to hack in a new connector. Once it cools off, I'm going to pull the shield from below and see if I'm getting voltage to the pump.

Pump1.png


Pump2.png
 

Nechaken

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Pretty simple job - took me about 90 min but if you regularly work on your car I'd guess you'd do it in half the time.

Here's a few notes for people doing it --

First, its clear my pump wasn't running at all. Applying 12V directly results in nothing. No idea when it failed and I only started looking into this when I got the "cooler efficiency" code under really extreme conditions, which I suppose is a testament to how durable (if not reliable) these rigs are, as well as the flexibility of modern engine management solutions. It probably wouldn't be a bad idea to verify yours is working. Either put a mechanic's stethoscope on it while the engine is running (easily reachable from the top) or pull the fuse box cover and jump the big terminals on Relay 15 to power the pump directly.

Pump is located on the driver's side - a little bit to the middle of the car and back from the coolant overflow tank.

1. Lift off the engine cover.
2. Remove the left air cleaner (remove maf connector and pull the power steering reservoir off the bracket first) and the bellows-like tube that goes to the plenum.
3. Service manual suggests removing the hoses from the pump from the top, but I couldn't get a good angle on the hose clamps -- I clamped the hoses shut car-side and pulled the hoses at A) the upper supercharger radiator hose right past the bleed valve and B) the junction where the pump output goes to a T for both of the intercoolers. I think this was advantageous -- when reinstalling, you have the two hoses on the top you can pre-fill with a coolant mixture to prime the pump and eliminate air space. I think I lost 4-6 oz of coolant through the whole job.
3. Go under the car (take safety precautions but you can do this in offroad height). Pull the middle metal cover (4 bolts, I want to say two are M6, two are M8). Pull the pop rivets out on the driver's side plastic cover and remove.
4. Look up and you'll see it.
5. Unplug the electrical connector (the harness has plastic slip clamps that hold it onto two coolant hoses).
6. Pump is held in a little plastic bracket - the side toward driver's is a plastic tab that fits in, and one nut (m4? m6?) on the side closer to the middle of the engine bay.
7. Pull the pump down and out (going to have to angle it a bit).
8. Transfer the inlet and output hoses to the new pump. Mine had white lines on the hoses for alignment - not sure if that was LR's doing or a previous mechanic's.
9. Thread the pump with hoses attached back up. There's a coolant hose running across the engine bay - the input hose goes in front of this hose, the pump outlet hose behind (toward rear of vehicle). I did this from the bottom, you could probably feed the pump down from the top as well, but it'd be a tight fit.
10. Fill the hoses going to the pump with coolant to prime it and reattach the hoses from where you removed them.
11. Put the little plastic bracket back across the pump (the tab is a bit of a pain to get in) and put the nut back on. Reattach the electrical connector and reattach the harness to the nearby coolant hoses.
12. Top up the coolant reservoir if it drained much.
13. I started the engine, let it warm up, then briefly opened the bleed screw at the supercharger radiator outlet. I believe this was enough -- Engine temp 1 slowly rises until about 205 F, then engine temp 2 starts rising, reflecting the thermostat opening. I don't believe any further bleeding was necessary -- I took the car for a ~ 30-minute drive and engine temp 1 never got above 212 degrees F and I had warm air front and rear. Given these cars' sensitivity to overheating, I'm certainly open to different opinions if there’s more for me to do on the bleeding angle?
 
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Nechaken

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Nice work! What pump did you end up going with?

Just the standard LR / Magna pump. I didn't want to screw around with finding a 2 pin connector to fit a Bosch and splicing into the factory wiring. Plus I wasn't sure if the stumpy pump mounting bracket was different than the earlier cars.

I saved the old pump to disassemble at a later time to see what exactly failed.
 

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