Hello,

I replaced coolant pump b with a Bosch unit purchased from Amazon:

Bosch Additional water pump 0 392 023 454

Engine is chpa

I believe it has worked since fitting end of May but now I have warning light and code p261b again.

My thoughts are - dodgy electrics, faulty pump or not correct replacement fitted?? It looked identical to the Bosch one I took out.

Any thoughts appreciated and be great if anyone can suggest correct part to try to replace with again that they know works.

Thanks

Hi, did you ever resolve this issue?

Hello. I changed the pump again this week. The replacement Bosch pump had failed and leaked into the electrical connection area just kike the original. Sadly simply replacing the pump has not cleared the error code and it is booked in to fix at garage tomorrow. I suspect the connector needs replacing again just like before.

Crazy failed already. Attached picture shows the failed pump. The pump still functioned just not communicating to car correctly I guess

36 minutes ago, wig02920 said:

Hello. I changed the pump again this week. The replacement Bosch pump had failed and leaked into the electrical connection area just kike the original. Sadly simply replacing the pump has not cleared the error code and it is booked in to fix at garage tomorrow. I suspect the connector needs replacing again just like before.

Crazy failed already. Attached picture shows the failed pump. The pump still functioned just not communicating to car correctly I guess

I think I have a wiring issue on mine too, the pins looks green and the pin on the ECU side is not pretty either!

Sounds like pump has leaked into electrical connector. That has happened twice to me now.

I will let you know how the garage sort it.

10 hours ago, wig02920 said:

Sounds like pump has leaked into electrical connector. That has happened twice to me now.

I will let you know how the garage sort it.

Yes, I'd be interested to know if they just replace the connector or if they replace the wiring back to ECU also. I'm going to try and trace the signal wire back to ECU today, there isnt much to get at immediately near the pump.

Garage called to say replacing everything.. pump, wiring and connector. I guess the original failure leaked for some time

Update

Ecu needed replacing as well as entire cable from pump to ECU. Additionally a bunch of neighboring wires at the ECU end were replaced as the damage went from pump to ECU and ecu to other connections.

It is working for now .

Garage said I have been unlucky.

1 minute ago, wig02920 said:

Update

Ecu needed replacing as well as entire cable from pump to ECU. Additionally a bunch of neighboring wires at the ECU end were replaced as the damage went from pump to ECU and ecu to other connections.

It is working for now .

Garage said I have been unlucky.

Mine was similar, I've since fixed it though. I managed to catch mine at the ECU plug, so was just able to wire in a new 60 pin ECU connector (which I got for £5 from scrapyard).

The tell was when my turbo actuator sensor signal wire started triggering a low voltage code, and I noticed this signal wire was right next to coolant pump B signal wire in the 60 pin ECU connector plug.

I think in the end I had to replace 3 pins in the connector plug as they had completely burnt off, was fiddly re-pinning the 60 wires into a new connector but satisfying once complete. Oh, I also had to replace the pins and connector at the pump end too, that was hard as there isnt much length on that piece of loom, I managed to get at it by moving the alternator back to free up a gap!

Has been fine ever since.