The fuel level sender changes resistance based on the fuel level. The engine control module (ECM)/powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is high and the ECM/PCM senses a high signal voltage. When the fuel tank is empty, the sender resistance is low and the ECM/PCM senses a low signal voltage. The ECM/PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The ECM/PCM sends the fuel level percent via the GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the instrument panel cluster (IPC) in order to display the fuel level percent on the fuel gage. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics.
This diagnostic tests for a stuck fuel level sender signal. The ECM/PCM sets this DTC if the fuel level sender signal appears to be stuck based on a lack of signal variation expected during normal operation.
This diagnostic procedure supports the following DTC:
DTC P0461 Fuel Level Sensor Performance
The ignition is ON, with the engine ON.
The ECM/PCM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 mi).
• | The fuel gage defaults to empty. |
• | The ECM/PCM records the operating conditions at the time the diagnostic fails. The ECM/PCM stores 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/PCM receives the clear code command from the scan tool. |
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, i.e. RPM, engine load, vehicle speed, temperature, etc. This will isolate when the DTC failed.
Refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Yes | No | ||||||
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Schematic Reference: Instrument Cluster Schematics Connector End View Reference: Powertrain Control Module Connector End Views for the 2.0L engine, Engine Control Module Connector End Views for the 2.2L engine, or Engine Control Module Connector End Views for the 2.4L engine | |||||||||
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 fuel level sender. Refer to the following:
Did you complete the replacement? | Go to Step 4 | -- | ||||||
4 |
Does the DTC reset? | Go to Step 2 | System OK |
Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Fuel Level Sensor Reference Voltage Circuit | P0462 | -- | P0461 | |
Fuel Level Sensor Signal Circuit | P0462 | P0463 1 | P0463 | P0461 |
Fuel Level Sensor Low Reference Circuit | -- | P0463 1 | P0463 | P0461 |
1. Fuel Gage Inaccurate or Inoperative. |
The fuel level sensor changes resistance in response to the fuel level. The engine control module (ECM) monitors the signal circuit of the fuel level sensor in order to determine the fuel level. When the fuel tank is full, the sensor resistance is low and the ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the ECM senses a high signal voltage. The ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The ECM sends the fuel level percentage via GMLAN serial data circuit to the body control module (BCM). the BCM sends the GMLAN message to the instrument panel cluster (IPC) in order to control the fuel gage and display the fuel level percent. Then fuel information is also used for misfire and evaporative emission (EVAP) diagnostics.
The engine is running.
The ECM does not detect a change in fuel level of at least 1.6 percent over a distance of 193 km (120 miles).
• | The fuel gage defaults to empty. |
• | The low fuel indicator illuminates. |
• | 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. |
⇒ | Repair any fuel level sender interference. |
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the ECM replacement, setup and programming. |