I have a 2000 Disco II. Cleared the codes on Monday and they came back today(P1412 and P1415). So far my research has turned up this.

P1412 SAI system fault (LH side) - air delivery not reaching catalysts
P1415 SAI system fault (RH side) - air delivery not reaching catalysts

The above system faults could be attributable to anything which might prevent air delivery to the exhaust manifolds (e.g. disconnected or blocked SAI delivery pipe, disconnected or blocked vacuum pipe etc.)

I looked the system over all vacuum lines appear to be in good shape/connected. I tested the SAI pump by supplying power to it with a test lead. The control valves are about a year old.

I read this write up P1413 trouble code [Archive] - Land Rover and Range Rover Forums and while great it lacks a key piece of information for me which is what system checks other than coolant temperature are performed when the system initializes.

The problem obvious to me is that the SAI pump is not coming on when the truck is cold. Today outside air temp was 39 degrees so the coolant would be plenty cold to cause the SAI pump to turn on. The pump does come on occasionally maybe 1 out of every 20 starts so I think the circuit is goes but only runs for 20 seconds or so not the 76 seconds described in that write up and not nearly as often as it should at initial start-up.

Can anyone recommend next steps for troubleshooting.

Thanks in advance.

 

Can't help you directly, but I can say that the SAI pump on mine also doesn't always run when cold, however, my SAI system is running fault free. So I'm thinking it's not always supposed to run.

 

I'll be tackling the same issue in about a weeks time (after LR D2 finally arrives on-island). One of the key bits of info is the following:

The engine control module (ECM) checks the engine coolant temperature when the engine is started, and if it is below 60 °C (131 °F) , the SAI pump is started. Secondary air injection will remain operational for a period controlled by the ECM (76 seconds for NAS vehicles, 64 seconds for EU-3 vehicles). The SAI pump operation can be cut short due to excessive engine speed or load.

If you have bridged the wires in the connector to test that the pump functions correctly, then it sounds like either the coolant temp is reading wrong or whatever controls the ECM interpreting high engine load and it is stopping it from runing the pump. Maybe connecting a scanner to read your engine temp at start-up could be a good first check? I mean I can't imagine at cold startup a temp over 131F.

If the pump is coming on at startup then the issue lies elsewhere. Of course this comes from reading other info and not practical experience - yet.....

Please keep the thread updated. As I said I'll be chasing these codes down next week.

Good luck,
Scott.

PS. I also found this info which may be helpful in diagnosis:

If you hear the high pitch hair drier/jet engine sound then its working but the housings loose/cracked or rivets are stretched. If you ONLY hear the deep exhuast leak noise and the SAI pump is plugged in, but it goes away after 30 seconds to a minute or so, then at least 1 of the vac solenoids are working properly, just not the pump. If you hear the SAI pump whine AND exhuast leak sound, then the exhuast tubing is lose or cracked somewhere.

 

Scott, thanks for the last paragraph I had not read that before or did not retain it if I did. I guess once I get the pump running on initial cold start up I can listen for those sounds. But my belie is that the rest of the system is in good shape.

What Island are you on.

 

I'm on St. Croix (USVI) and LR D2 should be shipped and arriving tomorrow (assuming it wasn't absconded with en-route) and cleared through customs by Wednesday. After that I'll be starting my SAI system diagnosis and will keep this thread updated.

 

I picked up LR D2 from the port yesterday and got it home. Began my familiarization with the new toy and read the codes. Sure enough P1412/1415 as expected. I began my diagnosis and immediately found a problem where the vacuum line connecting to the vacuum reservoir was not connected. So far this seems like a simple fix (too simple?). I plugged the line in and cleared the codes.

When LR D2 was shipped it had a quarter tank of gas, but it spent the week sitting on the docks in PR. The light was on when I picked it up. Some ***** had siphoned the gas out and tossed the gas cap. I got this surprise when fueling up. I hope to find a non-venting cap today at a local parts store - yea right!

So this morning with codes clear I could hear the whisper of the SAI pump start up and run for the prerequisite period without issue. Watched the temp on my sexy new ultragage peak at 204 which is expected for the stock thermo I guess. So far so good. I'll report back if the SAI problem re-rears it's ugly codes.

- Scott.

 

Scott,

Glad to hear you may have solved the problem so easily. Sorry to hear about the gas cap.


Anyone know which relay is for the SAI pump. I found the fuse that's intact and as I mentioned before I can jump power to the pump and make her run shes just not firing on her own so I need to verify the relay.

OK so now I found the relay its in the fuse box under the hood. If you stand beside the truck on the passenger side its the relay on the far right. Graphic on the fuse box cover is of an engine with a lightning bolt. Relay checks out. Verifyed power to pin 30 and that when power is applied to pin 87 the SAI pump spins right up.

So anyone have a thought on what to check next. My guess is I need to be able to see what the computer thinks the engine coolant and ambient air temp is. Anyone recommend a connector and software for a laptop solution or an inexpensive scanner?

What about the coolant sensor does anyone know if the ECU use the same sensor as the gauge inside the truck(that's working fine)?

Thanks all

Peter