Solution K91214678
Tuesday, March 6, 2018 5:43:19 PM CET

Solution
Title (customer effect)

Automated Manual Transmission ( AMT ) Faults - Diagnostic Trouble Codes ( DTCs )
P1052 - 18 , PID 33 FMI 5 Intermittent Fault In Cold Weather

Cause

When the weather gets colder, chassis equipped with an AMT ( I-Shift, mDrive ) may
set DTC P1052-18 or fault code MID 130 PID 33 FMI 5. The fault may then go inactive
after the unit warms up. An active fault in cold conditions can also go inactive after the
unit sits in a warm shop.

Solution
If the fault is always active regardless of conditions or is intermittent in warm
weather then there is a real failure of a component. Follow Guided Diagnostics ( GD )
in this situation. The fault will have to be ACTIVE during fault tracing to find the issue
and the unit may have to be operated in the conditions that trigger the fault.
Symptoms of this fault are:

1. Check for transmission messages on the Instrument Cluster ( IC )
2. Check lamp illuminated
3. Reduced clutch performance
4. Reduced gearbox comfort at start
5. Gear changes are slow

Conditions that activate this fault are:

1. Open circuit on any of the sensor signals is detected when one of the
sensor signals is within normal range and the other sensor signal is below
normal range
2. Open circuit on ground, detected when both the sensor signals are within
the normal range and the sum of the sensor signals is above a specific
value

If the unit drives normally and the fault lamp goes out after the unit warms up then
it is unlikely replacing a component will fix the issue.
If the chassis is equipped with an AMT-F, updated software is available to
correct a fault detection setting that made the condition worse. If the fault is
active, update the AMT-F gearbox to the latest software, then recreate the
conditions that triggered the fault. This may include letting the unit sit outside
overnight in cold weather and rechecking for the fault.
If the software does not improve the condition, replace the Clutch Position
Sensor.

There is not currently a software solution for the AMT-D gearboxes. Active
faults should be addressed by replacing the Clutch Position Sensor.

Internal comments (BO)

This is a known fault and is under investigation.
Recent data shows that the faults listed here are showing up at an increased rate.
The fault frequency data from Telematics Gateway ( TGW ) shows this to be a cold
weather related fault with virtually no faults occurring in the hotter months of the year.
The supplier of the position sensor has identified a possible root cause for this fault and
is in the process of verifing. The supplier of the sensor has identified a root cause with
the sensor and is currently working on a solution. For the short term, updating SW is
still the best option. A more agressive SW solution is being considered to bridge the gap
between current conditions and the release of the new sensor. Even with replacement of
the sensor the fault may still return.
Clutch position sensor part number 21695307.

Solution visibility

Dealer distribution

Function(s)/component(s) affected
Function affected

automatic transmission , Diagnostic tool

Function Group
Function Group

41 clutch , 431 gearbox, manual

Customer effect
Main customer effect

diagnostics/methodology , fault code/display

Road behaviour

driveability

Fault code(s)
OBD 2013 Diagnostic
Trouble Codes
NA_MIDs

POWERTRAIN , P1052 , P105218
MID 130 TECU

Conditions
Warning light/lamps
/pictograms
External temperature

yellow