Circuit Description
The Fuel Level sensor is an important input to the VCM for the Enhanced Evaporative System Diagnostic. The VCM needs the fuel level information in order to know the volume of fuel in the tank. The fuel level affects the rate of change in the air pressure in the EVAP system. Several of the Enhanced Evaporative System Diagnostic sub-test are dependent upon the correct fuel level information. The diagnostic will not run when the tank is greater than 85% or less than 15% full. (This sensor signal disables the misfire when the fuel levels are less than 15%).
Conditions for Running the DTC
The VCM has confirmed that the fuel tank is between 15 percent and 85 percent full.
Conditions for Setting the DTC
The VCM does not detect a decrease in fuel level over a distance of 200 miles(320 km).
Action Taken When the DTC Sets
| • | The control module stores the DTC in history after the first failure but will not illuminate the malfunction indicator lamp (MIL). |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores the failure information in the scan tools Freeze Frame/Failure Records. |
Conditions for Clearing the MIL or DTC
| • | The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
Diagnostic Aids
Check for the following conditions:
| • | A poor connection or damaged harness--Inspect VCM harness connectors for the following: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Poor wire to terminal connections |
| • | Intermittent test--monitor a scan tool or digital voltmeter connected between the related circuits while moving the connectors and harnesses. If the failure is induced, the voltage reading will change. This will help locate a circuit problem. |
Test Description
Number(s) below refer to the step number(s) on the diagnostic table.
-
This step determines if there is a 5V reference problem.
-
This step determines if the fuel level sender is responding to fuel level change.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. This information will be lost when the Clear DTC Information function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
2 |
Did the Fuel Level Sensor voltage change? | -- | ||||||||
3 | This DTC is intermittent. Are any additional DTC stored? | -- | Go to applicable DTC table | Go to Diagnostic Aids | ||||||
Is the voltage near the specified value? | 5.0V | |||||||||
5 | Repair the open or short to ground in the Fuel Level signal circuit. Refer to Wiring Repairs in Repair Instructions. Is action complete? | -- | -- | |||||||
6 | Check the Fuel Level Sender for the following:
Was a problem found? | -- | ||||||||
7 | Repair as necessary. Is the action complete? | -- | -- | |||||||
8 | Replace the Fuel Level Sender. Refer to Fuel Sender Assembly Replacement in Repair Instructions. Is the action complete? | -- | -- | |||||||
Did the Fuel Level Sensor voltage change? | -- | |||||||||
10 | Use the scan tool in order to display the Capture Info and the Review Capture Info functions. Are there any DTCs displayed that have not been diagnosed? | -- | Go to applicable DTC table | System OK |
