Perform the Diagnostic System Check - Instrument Cluster prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P2067 | -- | -- | P2066 |
Fuel Level Sensor Signal Secondary Circuit | P2067 | P2068 | P2068 | P2066 |
Fuel Level Sensor Low Reference Circuit | -- | P2068 | P2068 | P2066 |
The primary (left) fuel level sender and the secondary (right) fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender in order to determine the fuel level. When the fuel tank is full, the resistances of both fuel level senders are high and the ECM senses a high signal voltage on both the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender. When the fuel tanks are empty, the resistances of the fuel level senders are low and the ECM senses a low signal voltage. The ECM uses the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage.
The ignition is ON, with the engine ON.
• | The secondary sender output is less than 0.5 volt. |
• | The above condition is present for greater than 20 seconds. |
• | The fuel gage defaults to empty. |
• | The driver information center (DIC) illuminates the FUEL LEVEL LOW message. |
• | The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure Records on the scan tool. |
• | 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 ECM receives a clear code command from the scan tool. |
• | Engine Controls Schematics for the 4.6L engine |
• | Engine Control Module Connector End Views for the 4.6L engine |
Fuel Gage Description and Operation
With the scan tool installed and the ignition ON, the Fuel Tank Level Remaining parameter in the ECM EVAP Data List should indicate a value at or lower than 4 percent.
⇒ | If less than 98 percent, test the secondary signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the secondary (right) fuel level sensor. |
Perform the Diagnostic System Check - Instrument Cluster prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P2067 | -- | -- | P2066 |
Fuel Level Sensor Signal Secondary Circuit | P2067 | P2068 1 | P2068 | P2066 |
Fuel Level Sensor Low Reference Circuit | -- | P2068 | P2068 | P2066 |
The primary (left) fuel level sender and the secondary (right) fuel level sender changes resistance based on fuel level. The engine control module (ECM) monitors the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender in order to determine the fuel level. When the fuel tank is full, the resistances of both fuel level senders are high and the ECM senses a high signal voltage on both the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender. When the fuel tanks are empty, the resistances of the fuel level senders are low and the ECM senses a low signal voltage. The ECM uses the signal circuits of the primary (left) fuel level sender and the secondary (right) fuel level sender in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via serial data circuit to the instrument cluster in order to control the fuel gage.
• | The engine is running. |
• | The system voltage is between 10-18 volts. |
• | The secondary sender output is less than 0.25 volt. |
• | The secondary fuel level sensor signal range is about 5 percent. |
• | The above condition is present for greater than 60 seconds. |
• | The fuel gage defaults to empty. |
• | The driver information center (DIC) illuminates the FUEL LEVEL LOW message. |
• | The ECM records the operating conditions at the time that the diagnostic test fails. The ECM displays the failure information in the Failure Records on the scan tool. |
• | 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 ECM receives a clear code command from the scan tool. |
• | Engine Controls Schematics for the 3.6L engine |
• | Engine Control Module Connector End Views for the 3.6L engine |
Fuel Gage Description and Operation
With the scan tool installed and the ignition ON, the Fuel Tank Level Remaining parameter in the ECM EVAP Data List should indicate a value at or lower than 4 volts.
⇒ | If less than 4.5 volts, test the secondary tank signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If not within the specified range, replace the secondary (right) fuel level sensor. |