Grand Cherokee 4WD V8-4.7L (2003)
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PASS SELF TEST
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FAILED SELF TEST
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NOT RECEIVING J1850 MESSAGE
6. To exit the self-check mode, depress the RESET button or cycle the ignition switch and the EVIC will return to normal operation.
If a Communication fault is displayed, refer to the symptom list. If a FAILED is displayed, the EVIC must be replaced.
AMBIENT TEMPERATURE SENSOR
The ambient air temperature is monitored by the BCM and displayed by the EVIC. The BCM receives a hardwire input from the ambient temperature
sensor (ATS).
The ATS is a variable resistor that operates on a 5-volt reference signal circuit hardwired from the BCM. The resistance in the ATS changes as the
outside temperature rises or falls. The BCM senses the change in reference voltage through the ATS resistor. Based on the resistance of the ATS, the
BCM is programmed to correspond to a specific temperature. The BCM stores and filters the ambient temperature data and transmits this data to the
EVIC 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 BCM, and the
EVIC display
If the EVIC 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 EVIC 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 EVIC VFD can be tested.
The ATS is supported by the BCM. Ambient Temperature Sensor DTCs will be recorded in the BCM. The ATS can be diagnosed using the following
Sensor Test. Test the ATS circuits using the diagnostics in the Body Diagnostic Procedures Manual. If the EVIC passes the self test, and the ATS, the
circuits, and PCI bus communications are confirmed to be OK, but the EVIC temperature display is inoperative or incorrect, replace the BCM.
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:
Ambient 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 mm/max values. If the resistance values are not OK, replace the Sensor.
HOMELINK UNIVERSAL TRANSMITTER
If equipped, the HomeLink Universal Transmitter is integrated into the overhead console. For added security it will operate home security systems that
use coded signals known generically as Rolling Codes. The overhead console display provides visual feedback to the driver, indicating which
HomeLink transmitter channel button is being pressed. The HomeLink can learn and store up to three separate transmitter radio frequency codes to
operate garage door openers, security gates, and security lighting. The HomeLink buttons are marked with one, two, or three dots. For complete
information, refer to Universal Transmitter.
Exterior Lighting System
EXTERIOR LIGHTING SYSTEM
EXTERIOR LIGHTING BATTERY SAVER
The BCM monitors the status of and controls the park lamp, head lamp and fog lamp relay's. If any exterior lamps are left on after the ignition is
turned off, the BCM will turn them off after 8 minutes.
HEADLAMP DELAY
The headlamp time delay operates when the ignition switch is turned off while the headlamps are still on. This feature is customer programmable to
provide a 30, 60 or 90 second time delay before turning off the headlamps. This feature can also be disabled.
