Hi All

We have a problem on our 2004 S Type R.
Randomly and regularly it comes up with Restricted Performance and suddenly slows and loses power.

The error is P2601 Coolant pumpcontrol circuit range/performance.

Temp stays normal, no other errors. Pullover, switch off then on, then reset fault and all seems ok for a while (20 miles).

I changed the coolant pump for a new AVT. Check here: https://www.ebay.co.uk/itm/283133468099
Apparently better than OEM and better than Bosch.

All seemed fine for a few short trips but as it went to 20 miles or so it failed again.

Any idea? Is it a sensor failure?

I get an occasional P0430 come up, with bank 2 efficiently but this is just an O2 playing up.

The Cooling of the supercharger is worrying.

Thanks





P2601 Coolant pump control circuit range/performance.

 

A bit more detail, please. Did you change the coolant pump because of the message? Or did you change the pump for some other reason, and then the message started appearing?

These threads may be of interest:

https://www.jaguarforums.com/forum/s...p-mode-166944/

https://www.jaguarforums.com/forum/s...nt-pump-81392/

Different model, but still relevant:

https://www.jaguarforums.com/forum/x...ned-way-74007/

You mentioned the pump was replaced. Make sure you replaced the correct one, as there are two electric pumps on supercharged models. The "aux coolant pump" is found on all V8 models and primarily ensures adequate coolant flow to the heater core at low engine RPM. It only runs under certain conditions. The supercharger coolant pump is installed (wait for it...) only on supercharged models, with more details quoted from the link above:

"Somehow I got off on the wrong track with this. Code P2601 is NOT the Aux Coolant pump. Its the S/C coolant pump. Big difference in function and price. The S/C pump delivers coolant to the S/C intercooler, it's intertwined with the rest of the cooling system and the pump is on 100% of the time when the key is in the II position."

 

Hi

Thanks for the reply.
The pump was changed because of this error. The original pump was noisy, so we thought it would solve 2 problems.

If P2601 is the SC pump, then as I have changed that what else can it be?
The pump does run with the ignition in Pos II.

Thanks

 

OK fuse F36 15A blown. Replaced and ok.

Test driving now.

 

Oh well. If blew the fuse again.
Not sure when, 30 min drive, but no errors or messages.
Checked the fuse when I got home and it was blown.

Any thoughts?

 

This is a new problem, only started after replacing the pump? If so, it would seem your new pump is drawing too much current.

Could be the new pump is bad from stock. Or since you mentioned it was an upgraded design, maybe it draws more current by design than the original pump did.

 

Or wiring fault - maybe chafed?

 

Check the big connector around the wheel well. You have to remove the wheel and liner or get it up in the air and go from underneath. Just follow the plug wires and they go to a big connector. On my 06 str that connection had very bad corrosion and i had to bypass it for the charger pump. Worked great after that

 

Thanks for the advice guys. All good.

The company I got the pump from have offered to send another. I am going to swap over the relay before that and put a new fuse in. It did not blow when at idle as I checked the voltage either side. I wonder if it is worth putting a 20A fuse in..... What are your thoughts on that? Maybe the pump does take a little more current.

I will check the conncector for corrosion too, I have had similar on other cars causing small surges in current as it connects and breaks then connects. Will also check for chaffing.

Thanks

 

Well I suspect that there is no point in changing the relay as it's the ignition coil relay, which clearly is working ok.


Connection on Intercooler pump

Power to Intercooler pump comes from the Ignition coil relay.

So back to looking for chaffing, corrosion or trying a 20A fuse in place of the 15A.

 

Update.
Seems to be a pump failure. Strange being brand new, but these things happen (why always to me?).

It started and ran ok for a few mins, certainly 12V applied to it from measuring on the fuse F36.
I left it running 5 mins and came back to find the fuse had blown and the pump body too hot to touch. Coolant pipes were still cool so not hot from coolant.

Oh well. Replacement requested.

Update next week.

 

Good find on the pump getting hot. It can be a troubleshooting nightmare to have new parts bad from stock, but you seem to have a good handle on it.

Re: The ignition coil relay. If you have a spare, it would not hurt to replace it. As you noticed, the intercooler pump gets its power supply from the same relay powering the ignition coils. And yes, the relay is obviously working, at least to some extent. But I also suspect the ignition coils are more tolerant of low voltage. Say the contacts inside the relay are damaged from arcing. I'm talking about the on/off output side, not the electromagnet control portion. The contacts could be switching on/off as commanded, but have developed enough corrosion so only 10v or so is reaching the coils. That may be enough for the coils to still fire (it's entirely normal for battery voltage to dip close to 10V with the starter engaged), but this low voltage could affect the pump.

Certain types of high torque electric motors can go into a weird failure mode with a reduced voltage supply. The motor still tries to put out X amount of force, but draws lots of extra current doing so. Extra current = extra heat, so maybe that's what you're seeing. Kind of a long shot, so don't put too much stock in it. But it wouldn't hurt to swap that relay with a known good donor and see if that helps.

Still, most likely it's just a pump that was bad from stock. The old one failed in a totally different manner, with a mechanical failure of the bearings causing excess noise. That pump was never blowing fuses. The new problem (blown fuses) didn't start until you installed the new pump.

 

Something else unusual I noticed: I didn't see any monitoring of the pump, so am unsure what flags the P2601 fault code. Nothing monitors the amp draw or speed of the pump. The ignition coil relay switched power on/off to the pump.

The only thing I could see is the supercharged models have an "Inlet Air Temperature 2" sensor, not found on normally aspirated models. See figure 03.5 here, towards the left at the bottom of the diagram:

http://www.jagrepair.com/images/Auto...x2062004en.pdf

Strictly conjecture on my part, but perhaps if monitors the air temperature downstream of the cooler. If too warm under given conditions, maybe it flags that as a pump failure.

 

Basically it monitors IAT2 - a bad pump fails to cool the supercharged air (you can figure it out or of course read the Jaguar/Denso doc LOL).

 

By Jaguar/Denso doc, do you mean the S Type Electrical guide? Or is there another?

 

There are lots of docs - here, the large file area, and JagRepair.com - Jaguar Repair Information Resource and of course they can be for the STR, XJR, XKR, etc.

 

Update.
New pump fitted. We tested it before fitting and all was ok.
Once it was on we put a new fuse in and checked the pump for operation (noise and movement) with the ignition on. All seems ok.
After 10-20 mins running the pump was warm to the touch and certainly not hot. The pipes were not hot yet, but then is was just idling while it was being bled.

The old pump was hooked to an external battery and there was just a spark upon contact and no movement in the pump. So it is a dud.
Will try a test drive later.

Thanks

 

ok another update.

Test drive for 20-30 minutes, get home and the pump is red hot again and the fuse has blown.

That is 2 brand new pumps killed.

What is doing this? It cannot be a bad run on pumps, the chances are against that surely.

Not sure I can take much more of this car...... such a shame :-(

 

Pulled apart the aftermarket pump, it seems to have seized where the plastic was rubbing against itself. I presume the other pump they supplied has done the same.
What are the Bosch pumps like? Are there any good pumps out there?

We pulled apart the OEM pump too, that had a dodgy impeller so it seemed, but upon putting it back together its freed up and moved more air on power-up than the aftermarket one.

Thanks
James

 

One thought: The pump handles coolant at approximately 200F. Sounds like the pump has other problems, but being hot to the touch may not be a fault in itself.