Low Range Light Flashes, Code P1831 (28.19/05A)

Publication date: 2004-05-05
Reference number: 28.19/05A

LOW RANGE LIGHT FLASHES, CODE P1831

TECHNICAL SERVICE BULLETIN

Reference Number(s): T-B-28.19/05A, Date of Issue: May 5, 2004

MERCEDES-BENZ:	Model 163.154/157/174/175, as of Chassis # A346835
GROUP:	28 - Transfer case

Superceded Bulletin(s): T-B-28.19/05, Date of Issue: April 26, 2004

NOTE: Revision: Technical Update

SUBJECT

Model 163.154/157/174/175, as of Chassis # A346835

low Range Light Flashes, Code P1831

SERVICE INFORMATION

If you receive customer reports in the above model vehicles of the low Range light flashing rapidly (18 times) after vehicle start with fault code P1831 (Positioner motor, position sensor or power supply is faulty) in transfer case ECU, do not replace the transfer case motor. This is caused by temporary loss of communication between transfer case control module and shift motor position sensor. To resolve, read out fault codes and cycle transfer case shift motor by following the below procedure.

Read out and erase fault codes.
If fault codes other than P1831 are present, diagnose and repair accordingly (use appropriate damage code, operation code and time).
If fault code P1831 is present, start vehicle.
Shift transmission into neutral (N).
Push LOW RANGE switch. Depress brake pedal.
After shift motor has cycled, push LOW RANGE switch again. LOW RANGE light should go out at this time.
Confirm proper transfer case shift function: Cycle ignition and repeat steps 2-5.

WARNING: While performing the transfer case shift adaptation described above, take all necessary safety measures such as applying the parking brake and holding the service brake firmly. (Failure to do so can result in unintended vehicle movement.)

NOTE: The following allowable labor operations should be used when submitting a warranty claim for this repair.

IN CASE OF WARRANTY

Operation:

Short test, perform (54-1011)

Transfer case shift motor - reset (after test), perform (02-4319)

WARRANTY INFORMATION

Damage Code	Operation Number	Time (hrs.)	Model Indicator (s)
28164 73	54 1011	0.3 hrs.	00
28164 73	02 4319	0.2 hrs.	K1, K3, K4, K5