Circuit Description
The powertrain control module (PCM) monitors the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to determine fuel level. Each sender consists of a variable resistor that changes resistance based on fuel level in both tanks. The PCM monitors the voltage across both sender resistances in order to determine the fuel level. The PCM uses the signal circuits of the primary fuel level sender and the secondary fuel level sender in order to calculate the total remaining fuel, in percent. The PCM sends the fuel level percent via serial data circuit to the instrument cluster in order to control the gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.
This diagnostic tests for a stuck secondary fuel level sensor signal. The PCM sets this DTC if the secondary fuel level sensor signal appears to be stuck based on a lack of signal variation expected during normal operation.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2066 Fuel Level Sensor 2 Performance
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The PCM does not detect a change in the secondary fuel level of at least 3 L (0.79 gal) over a distance of 320 km (200 miles).
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The PCM records the operating conditions at the time that the diagnostic test fails. The PCM displays the failure information in the Failure Records on the scan tool. |
Conditions for Clearing the DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction-free warm-up cycles. |
| • | The PCM receives the clear code command from the scan tool. |
Diagnostic Aids
| • | For the 6.6L (LLY) engine, failure of the transfer fuel pump can set this DTC. Refer to DTC P2636 |
| • | Use the Freeze Frame/Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data may help in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also help in determining the number of ignition cycles that the diagnostic test reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions, including those for RPM, for engine load, for vehicle speed, for temperature, and for others. This will isolate at what point the DTC failed. Refer to Testing for Intermittent Conditions and Poor Connections . |
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Master Electrical Component List | ||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||||
2 |
Did you find and correct the condition? | -- | Go to Step 4 | Go to Step 3 | ||||||||
3 | Replace the secondary fuel level sensor. Refer to one of the following procedures:
Did you complete the replacement? | -- | Go to Step 4 | -- | ||||||||
4 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||||
