Temperature Display Inaccurate or Inoperative
TEMPERATURE DISPLAY INACCURATE OR INOPERATIVEPOSSIBLE CAUSES
- Ambient temperature sensor
- Electronic overhead module
1. AMBIENT TEMPERATURE SENSOR
NOTE:
- Diagnose and repair any FCM, EOM, PCM, or Communication DTCs before proceeding with this test.
- The Ambient Temperature Sensor is hardwired to the FCM (Diesel), or to the PCM. Ambient temperature information is transmitted to the EOM via the PCI Bus.
Turn the ignition off.
Disconnect the Ambient Temperature Sensor harness connector.
Measure the resistance of the Ambient Temperature Sensor using the following temperature/resistance values:
10° C (50° F) Sensor Resistance = 17.99 - 21.81 Kilohms
20° C (68° F) Sensor Resistance = 11.37 - 13.61 Kilohms
25° C (77° F) Sensor Resistance = 9.12 - 10.88 Kilohms
30° C (86° F) Sensor Resistance = 7.37 - 8.75 Kilohms
40° C (104° F) Sensor Resistance = 4.90 - 5.75 Kilohms
50° C (122° F) Sensor Resistance = 3.33 - 3.88 Kilohms
Q: Is the Ambient Temperature Sensor resistance measurement within the min/max specifications?
YES: Go To 2
NO: Replace the Ambient Temperature Sensor. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
2. ELECTRONIC OVERHEAD MODULE
Perform the EOM Self Test. Self-Diagnostic Test
Turn the ignition off.
Press and hold the C/T and Reset buttons.
Turn the ignition on.
NOTE: NOTE: The self test can also be performed using the DRBIII(R).
Observe the EOM display at the conclusion of the self test.
Q: Does the EOM display "Passed Self Test"?
YES: Test Complete.
NO: Replace and configure the EOM. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test