DTC P0462 2.0L and 2.2L
Circuit Description
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 that 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 lower than normal fuel level sender signal.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0462 Fuel Level Sensor Circuit Low Voltage
Conditions for Running the DTC
The ignition is ON, with the engine ON.
Conditions for Setting the DTC
| • | The fuel level signal is less than 3.5 percent. |
| • | The above condition is present for greater than 5 seconds. |
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The ECM/PCM records the operating conditions at the time the diagnostic fails. The ECM/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 ECM/PCM receives the clear code command from the 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, 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 .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
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 |
Does the scan tool indicate that the Fuel Tank Level Remaining parameter is less than the specified value? | 3.5% | Go to Step 3 | Go to Diagnostic Aids | ||||||
Does the scan tool indicate that the Fuel Tank Level Remaining parameter is greater than the specified value? | 98% | Go to Step 5 | Go to Step 4 | |||||||
4 | Test the signal circuit of the fuel level sender for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 7 | ||||||
5 | Test the signal circuit of the fuel level sender for a short to ground between C305 and the fuel level sender. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 | ||||||
6 | Inspect for poor connections at the harness connector of the fuel level sender. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 | ||||||
7 | Inspect for poor connections at the harness connector of the ECM/PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 | ||||||
8 | Replace the fuel level sender. Refer to the following:
Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
9 | Replace the ECM/PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 10 | -- | ||||||
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK | ||||||
DTC P0462 2.4L
DTC Descriptor
DTC P0462: Fuel Level Sensor Circuit Low Voltage.Diagnostic Fault Information
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. | ||||
Circuit/System Description
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.
Conditions for Running the DTC
| • | The ignition is ON, with the engine running. |
| • | The system voltage is between 9-16 volts. |
Conditions for Setting the DTC
| • | The sender output is less than 0.39 volts. |
| • | The above condition is present for greater than 30 seconds. |
Action Taken When the DTC Sets
| • | 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 |
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 ECM receives a clear code command from the scan tool. |
Reference Information
Fuel Level Specifications
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
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 greater than 98 percent.
Circuit/System Testing
- Ignition OFF, disconnect the fuel level sensor connector.
- Ignition ON, with the scan tool observe the Fuel Tank Level Remaining parameter. Verify the Fuel Tank Level remaining parameter is 4 percent or less.
- If all circuits tests normal, test or replace the fuel level sensor.
| ⇒ | If the Fuel Tank Level Remaining parameter indicates a value greater than 4 percent, test the fuel level sensor signal circuit for a short to ground. If the fuel level sensor circuit tests normal, replace the ECM. |
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for the PCM/ECM replacement, setup and programming. |
