RAM 3500 Truck 2WD L6-5.9L DSL Turbo VIN C (2003)
receives a hardwire input from the ambient temperature sensor (ATS). For 4.7L and 5.7L equipped vehicles, the NGC receives the hardwire input
from the ATS.
The ATS is a variable resistor that operates on a 5-volt reference signal circuit hardwired from the FCM or NGC. The resistance in the ATS changes
as the outside temperature rises or falls. The FCM or NGC senses the change in reference voltage through the ATS resistor. Based on the resistance of
the ATS, the FCM or NGC is programmed to correspond to a specific temperature. The FCM or NGC stores and filters the ambient temperature data
and transmits this data to the CMTC via the PCI Bus. The ATS cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
Ambient Temperature Sensor Fault Codes
The outside temperature function is supported by the ambient temperature sensor (ATS), a signal and ground circuit hardwired to the FCM or the
NGC, and the CMTC display.
If the CMTC display indicates 54 °C (130 °F) or the ATS sense circuit is shorted to ground, the temp display will be 54 °C (130 °F) to indicate a
SHORT circuit condition.
If the CMTC display indicates -40 °C (-40 °F) or the ATS sense circuit is open, the temp display will be -40 °C (-40 °F) to indicate an OPEN circuit
condition.
If there is an OPEN or SHORT circuit condition, it must be repaired before the CMTC VFD can be tested.
The ATS is supported by the FCM. Ambient Temperature Sensor DTCs will be recorded in the FCM. The ATS can be diagnosed using the following
Sensor Test. Test the ATS circuits using the diagnostics in the Body Diagnostic Procedures. If the CMTC passes the self test, and the ATS, the
circuits, and PCI bus communications are confirmed to be OK, but the CMTC temperature display is inoperative or incorrect, replace the FCM or
NGC as required.
Ambient Temperature Sensor Test
1. Turn the ignition OFF.
2. Disconnect the ATS harness connector.
3. Measure the resistance of the ATS using the following min/max values:
Temperature
Sensor Resistance
0 °C (32 °F)
29.33 - 35.99 Kilohms
10 °C (50 °F)
17.99 - 21.81 Kilohms
20 °C (68 °F)
11.37 - 13.61 Kilohms
25 °C (77 °F)
9.12 - 10.86 Kilohms
30 °C (86 °F)
7.37 - 8.75 Kilohms
40 °C (104 °F)
4.90 - 5.75 Kilohms
The sensor resistance should read between these min/max values. If the resistance values are not OK, replace the Sensor.
Electronic Vehicle Information Center (EVIC)
When equipped, the Electronic Vehicle Information Center is located in the overhead console. The EVIC performs all of the same functions as a
Compass Mini-Trip Computer (CMTC). The EVIC also provides additional driver information, warnings; an interface to enable and disable vehicle
programmable features and display memory system messages. The EVIC is integrated with the Universal Garage Door Opener (UGDO) known as
HomeLine. The EVIC function buttons are labeled MENU, STEP, CAL, and RESET.
All of the EVIC features are the same as the CMTC, with the following additional features:
WARNING MESSAGES: when the appropriate conditions exist, the EVIC displays the following warning messages and symbols. Each message is
accompanied by a series of beeps.
-
TURN SIGNALS ON (with graphic)
-
TURN SIGNAL OUT (with graphic)
-
PERFORM SERVICE
-
DOOR OPEN (One or more, with graphic)
-
WASHER FLUID LOW (with graphic)
-
RKE FOB BATTERY LOW
-
LAMP OUT (with graphic) for Headlamp, Tarn Lamp, and Brake Lamp
CUSTOMER PROGRAMMABLE FEATURES: Press the MENU button to select one of the following displays:
-
LANGUAGE (Press STEP button to select one of 5 languages)
-
US or METRIC (Press STEP button to toggle between US or Metric units)
-
AUTO DOOR LOCKS (Press STEP button to select "Yes" or "No").
-
AUTO UNLOCK ON EXIT (Press STEP button to select "Yes" or "No").
-
REMOTE UNLOCK DRIVER'S DOOR 1st (Press STEP button to select)
-
SOUND HORN ON LOCK (Press STEP button to select)
