P15D1

20A801 - P15D1

Information saved in
DME

Fault code
20A801 - P15D1

Fault text
Coolant pump, deactivation: internal temperature too high

Fault description
The diagnostic function monitors the temperature of the
electric water pump's electronics.

Condition for fault identification
Test condition:
The fault is recognized when the temperature of the water
pump's electronics is >136 °C. A power reduction is entered.
Potential problem source(s):
- Electric fan defective
- Coolant thermostat defective
- Insufficient coolant
- Defective water pump
Terminal condition: none
Voltage condition:
- Onboard electrical system voltage between 9 V and 16 V
Temperature condition:
- None
Time condition:
- None
Other conditions:
- Engine on
- No BSD fault

Condition for fault memory entry
The diagnostic fault code is logged when the fault remains
present for longer than 1 min.

Action in service
- Continue testing with test modules focusing on problems
with the electric fan and the thermostat
- Start engine, set heat to maximum output, allow to run for
5 minutes and the check to determine whether the diagnostic
fault code has been logged again
- If the diagnostic fault code continues to appear despite
correct engine temperature replace the water pump

Fault effect and breakdown warning
Breakdown notice:
None
Possible apparent symptoms:
CC message if engine becomes too hot, breakdown in
extreme cases

Driver information
Warning light:
- ECE emissions warning lamp: off
- ECE electronic engine power reduction: off
- CC message: on
- US emissions warning lamp: off
- US electronic engine power reduction: off
- CC message: on

Service instruction
Observe sequence for fault rectification:
- If the pump is activated at TMOT>90 °C as tester job the
diagnostic fault code 0x3792 or 0x20AD08 'Water pump:
rotation speed implausible' can be logged, ignore this fault
and delete it --> Carry out tester job at Tmot<90 °C