Bosch PCE Coolant Pumps
Important Note on Bosch vs VW pumps
Although both companies use pumps from the "PCE"-series, a closer look at the pump connector reveals an important difference: Bosch pumps have the key nearer to the centre (pin 2) and have the pinout 1 (gnd), 2 (signal), 3 (12V). By contrast, VW pumps have the key closer to the leftmost pin (pin 1) and have the pinout 1 (gnd), 2 (12V), 3 (signal). Also note that, although both brands have "Bosch" on the label, the VW-branded ones also have a "VW-AG" marking.
Connector Part Numbers [1][2]
VW pumps
Pigtail
- VW: 4F0 973 703
Housing
- TE Connectivity "MCON 1.2" series: 1488991-5 (key A)
- Molex "MXP120" series: 34900-3101 (key A)
Terminals
- Bosch: 1 928 498 811
- Tyco/Molex MCON 1.2" series: 1670146-3 – Ag plated (20awg)
- KOSTAL MLK 1.2: 32124734130
Seal
- Bosch: 1 928 300 936
- TE Connectivity: 967067-1 (20 awg)
- KOSTAL: 10800507250
Pinout
Bosch pumps
Housing
- TE Connectivity "MCON 1.2" series: 1488991-6 (key B)
- Molex "MXP120" series: 34900-3102 (key B)
Terminals
- Bosch: 1 928 498 811
- Tyco/Molex MCON 1.2" series: 1670146-3 – Ag plated (20awg)
- KOSTAL MLK 1.2: 32124734130
Seal
- Bosch: 1 928 300 936
- TE Connectivity: 967067-1 (20 awg)
- KOSTAL: 10800507250
Pinout
Operation
Pump can be run without the signal (S) pin connected. This will operate the pump at maximum speed. There is a 2 second startup delay if the pump is to be operated without the signal (S) pin connected.
If the pump detects that it is being run dry, it will turn itself off, try again, but will quit if unsuccessful >20 times
Signal pin can be provided a 12v PWM to control the speed[3]