DTC P0461 2.0L - L34 GMDAT
Circuit Description
The fuel level sensor changes resistance based on fuel level. The fuel level sensor has a signal circuit and a ground circuit. The engine control module (ECM) applies 5.0 volts on the signal circuit to the sensor. The ECM monitors the changes in this voltage caused by changes in the resistance of the sensor in order to determine fuel level.
When the fuel tank is full, the sensor resistance is low, and the ECM signal voltage is high. When the fuel tank is empty, the sensor resistance is high, and the signal voltage is low.
The ECM uses inputs from the fuel level sensor in order to calculate the total fuel percentage remaining in the fuel tank. The ECM uses the fuel level information for the EVAP and misfire diagnostics. The fuel level information is sent to the instrument panel cluster (IPC).
This diagnostic tests for a stuck fuel level sensor signal. If the fuel level signal appears to be stuck, based on a lack of signal variation expected during normal operation, this DTC sets.
DTC Descriptors
This diagnostic procedure supports the following DTC:
DTC P0461 Fuel Level Sensor Circuit Performance
Conditions for Running the DTC
| • | DTCs P0462, P0463, and P0502 are not set. |
| • | The engine is operating. |
| • | DTC P0461 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM does not detect a decrease in fuel level over a distance of 250 Km (155 miles).
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the third consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
| • | The fuel gage defaults to empty. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
Check for the following conditions:
| • | A poor connection or damaged harness -- Inspect ECM 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. Refer to |
| • | For an intermittent condition, refer to Intermittent Conditions in Engine Controls - 2.0L (L34). |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the fault is present.
-
This step determines if the fuel level sensor signal and ground circuits are OK.
Step | Action | Value | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check - in Instrument Cluster? | -- | ||||||||
|
Important: : If DTCs P0462 or P0463 are also set, diagnose those DTCs first. Refer to DTC P0462 or DTC P0463 .
Is the fuel level voltage at the specified value? | 5.0 V | |||||||||
Is the fuel level sensor voltage near the specified value? | 5.0 V | |||||||||
4 |
Refer to Fuel Sender Assembly Replacement in Engine Controls - 2.0L (L34).
Did you find and correct the condition? | |||||||||
5 | Test the fuel level signal sensor circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||||
6 | Test the low reference circuit and the fuel level signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||||
7 | Replace the fuel level sender assembly. Refer to Fuel Sender Assembly Replacement in Engine Controls - 2.0L (L34). Did you complete the replacement? | -- | -- | |||||||
8 | Test for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||||||||
9 | Replace the control module. Refer to Engine Control Module Replacement in Engine Controls - 2.0L (L34). Did you complete the replacement? | -- | -- | |||||||
10 |
Did the DTC fail this ignition? | -- | ||||||||
11 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.0L (L34) | System OK | ||||||
DTC P0461 2.5L - LBK
Circuit Description
The fuel level sensor changes resistance based on the amount of fuel in the fuel tank. The fuel level sensor has a common, or shared 5-volt reference circuit and a signal circuit. The engine control module (ECM) applies 5.0 volts on the reference circuit to the sensor. The ECM monitors the changes in this voltage on the signal circuit, caused by a change in the resistance of the fuel level sensor, in order to determine fuel level.
When the fuel tank is full, the sensor resistance is low, and the ECM signal voltage is high. When the fuel tank is empty, the sensor resistance is high, and the signal voltage is low.
The ECM uses inputs from the fuel level sensor in order to calculate the total fuel percentage remaining in the fuel tank. The ECM uses the fuel level information for the EVAP and misfire diagnostics. The fuel level information is sent to the instrument panel cluster (IPC).
This diagnostic tests for a stuck fuel level sensor signal. If the fuel level signal appears to be stuck, based on a lack of signal variation expected during normal operation, this DTC sets.
DTC Descriptors
This diagnostic procedure supports the following DTC:
DTC P0461 Fuel Level Sensor Circuit Performance
Conditions for Running the DTC
| • | The engine is operating. |
| • | DTC P0461 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM does not detect a change in fuel level of more than 5.88 percent for an accumulated time of more than 5 hours.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
| • | The fuel gage defaults to empty. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.). This will isolate when the DTC failed.
Check for the following conditions:
| • | A poor connection or damaged harness -- Inspect ECM harness connectors for the following: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Poor wire to terminal connections |
| • | For an intermittent condition, refer to Intermittent Conditions in Engine Controls - 2.5L. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the signal circuit for a short to voltage. If the scan tool displays a voltage after the fuel sender assembly harness connector is disconnected, the circuit is shorted to a voltage.
-
This step tests for a condition in the 5-volt reference circuit of the fuel level sensor. If the DMM does not display more than the specified voltage, test for an open or for a high resistance in the 5-volt reference circuit.
-
If the Fuel Level Voltage parameter does not display more than the specified voltage, test for an open, or for a high resistance in the signal circuit.
-
Inspect the fuel sender assembly harness connector, internally and externally, for water intrusion, corrosion, and bent or damaged terminals.
-
Inspect the ECM connectors for water intrusion, corrosion, and bent or damaged terminals.
Step | Action | Value | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Instrument Panel, Gages, and Console Connector End Views | ||||||||||
1 | Did you perform the Diagnostic System Check - in Instrument Cluster? | -- | ||||||||
2 |
Is DTC P0462 or P0463 also set? | -- | Go to Step 3 | |||||||
Is the voltage less than the specified value? | 0.02 V | Go to Step 4 | Go to Step 6 | |||||||
Important: Use the J 35616-200 Test Lamp Kit for this test. If the J 35616-200 is not available, use a test lamp that measures more than 20 ohms. Is the voltage more than the specified value? | 4.8 V | Go to Step 5 | Go to Step 8 | |||||||
Is the voltage less than the specified value? | 4.8 V | Go to Step 7 | Go to Step 9 | |||||||
6 | Test the signal circuit of the fuel level sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
7 | Test the signal circuit of the fuel level sensor for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
8 | Test the 5-volt reference circuit of the fuel level sensor a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11 | ||||||
9 |
Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 | ||||||
Test for shorted terminals and poor connections at the fuel sender assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 | |||||||
Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | |||||||
12 | Replace the fuel sender assembly. Refer to Fuel Sender Assembly Replacement in Engine Controls - 2.5L. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
13 | Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls - 2.5L. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
14 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 15 | ||||||
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.5L | System OK | ||||||
