*** Mini Cooper technical Problem and SolustionM1220105
Cooling System - SES Lamp ON/DTC P0128 Set
Service Measure
Engine Electrical
M12 201 05
Date: 0503252004 Mini Cooper (R50) L4-1.6L (W10)
Page 97
03/25/2005
Subject
DME (EMS2000 or MS5150) Fault Code P0128 - Coolant Thermostat
Model
R50 (Cooper) R52 (Cooper and Cooper S) and R53 (Cooper S) equipped with W10 and W11 engines.
Complaint
The customer complains the Service Engine Soon Lamp is illuminated. When diagnosed the following fault is found in the DME (EMS2000
or M55150) memory.
Fault Code P0128 - Coolant thermostat coolant temp below thermostat control temp
Cause
An air pocket in the cooling system can cause operational errors of the cooling system causing faults to store in memory. One of the
following areas can be the cause.
1. Air pockets near the engine thermostat can cause the thermostat to have a delayed opening. This will cause a slight over
temperature in the engine cooling system for short period of time signaling the DME with incorrect data via the coolant temperature
sensor.
2. Air pockets near the engine coolant temperature sensor can incorrectly inform the DME of proper engine temperature during the
warm up phase.
If the DME is supplied with incorrect cooling data during the warm up phase then the calculation for the virtual radiator outlet temperature
can also be inaccurate causing the above fault to store in memory.
Measure
1. Bleed cooling system.
2. Do not replace any parts.
3. Connect vehicle to a FASTA transmitting diagnostic device and perform short test. Once the short test has concluded verify the
vehicle has been identified properly.
4. If a resolution cannot be found through bleeding of the cooling system then please submit a PuMA Case to the Drivetrain Technical
Hotline before proceeding with any further repairs.
