RAM 1500 Truck 2WD V6-3.9L VIN X (1999)
Compass Variance
Compass Variance is the difference between Magnetic North and Geographic North. In some areas of the country, the difference between
Magnetic and Geographic North is great enough to cause the compass to give false readings. If this occurs, the compass variance must be set.
To set the variance: Turn the ignition ON and set display to Comp./Temp. Simultaneously press both the US/M and STEP button for 0 to 2
seconds. The VAR indicator will light up and the current zone number will be displayed. Press STEP button to select the proper variance zone as
shown on the map. After 5 seconds of inactivity, the displayed zone will be automatically set, and normal operation will resume.
Diagnostics
CTM is fully addressable with the DRB III and it is the recommended method for diagnosis. The CTM reports 6 Diagnostic Trouble Codes. All of the
inputs to the CTM can be read with the DRB and the outputs can be actuated. If the inputs are OK and the outputs can be cycled with the DRB, the
problem is usually the Central Timer Module.
DRB III Error Messages and Blank Screen
Under normal operation, the DRB will display one of only two error messages:
-
User-Requested WARM Boot or User-Requested COLD Boot.
If the DRB should display any other error message, record the entire display and call the MDS Hotline, or call for information and assistance at
1-800-825-8737. This is a sample of such an error message display:
Ver:
2.14
date: 26 Jul93
file:
key_itf.cc
date: Jul 26 993
line:
548
err:
Ox1
User-Requested COLD Boot
Press MORE to switch between this display and the application screen.
Press F4 when done noting information.
DRB III does not power up (Blank Screen)
If the LED's do not light or no sound is emitted at start up, check for loose cable connections or a bad cable. Check the vehicle battery voltage
(data link connector cavity 6). A minimum of volts is required to adequately power the DRB.
If all connections are proper between the DRB and the vehicle or other devices, and the vehicle battery is fully charged, an inoperative DRB may
be the result of faulty cable or vehicle wiring.
DRB III
Display is not visible
Low temperatures will affect the visibility of the display. Adjust the contrast to compensate for this condition.
Enhanced Accident Response (Highline CTM Only)
If the Airbag Control Module (ACM) deploys the airbags, a message is transmitted over the CCD bus to the CTM module to unlock the doors. The
interior lights will be turned ON seconds after getting zero speed message on the CCD bus.
