DTC P0462 Sedan
Circuit Description
The fuel level sender changes resistance based on the fuel level. The powertrain control module (PCM) or the engine control module (ECM) monitors the signal circuit of the fuel level sender in order to determine the fuel level. When the fuel tank is full, the sender resistance is high and the PCM/ECM senses a high signal voltage. When the fuel tank is empty, the sender resistance is low and the PCM/ECM senses a low signal voltage. The PCM/ECM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The PCM/ECM sends the fuel level percent via the GMLAN serial data circuit 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.
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 0.4 volt or 2 percent. |
| • | The above condition is present for greater than 5 seconds. |
Action Taken When the DTC Sets
| • | The fuel gage defaults to empty. |
| • | The low fuel indicator illuminates. |
| • | The PCM/ECM records the operating conditions at the time the diagnostic fails. The PCM/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 PCM/ECM 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 2.2L engine, Powertrain Control Module Connector End Views for the 3.5L engine or Engine Control Module Connector End Views for the 3.9L 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 C413 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 PCM/ECM. 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 PCM/ECM. 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 Extended Sedan
DTC Descriptor
DTC P0462: Fuel Level Sensor Circuit Low VoltageDiagnostic 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 powertrain control module (PCM) or 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 PCM/ECM senses a low signal voltage. When the fuel tank is empty, the sensor resistance is high and the PCM/ECM senses a high signal voltage. The PCM/ECM uses the signal circuit of the fuel level sensor in order to calculate the percentage of remaining fuel in the tank. The PCM/ECM sends the fuel level percentage via GMLAN serial data circuit to the body control module (BCM). The BCM sends a GMLAN message to the instrument panel cluster (IPC) in order to display the fuel level percent on the fuel gage. The 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 volt. |
| • | 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 PCM/ECM records the operating conditions at the time that the diagnostic test fails. The PCM/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 PCM/ECM receives a clear code command from the scan tool. |
Reference Information
Fuel Level Specifications
Schematic Reference
| • | Engine Controls Schematics for the 2.2L engine |
| • | Engine Controls Schematics for the 3.5L engine |
| • | Engine Controls Schematics for the 3.9L engine |
Connector End View Reference
| • | Powertrain Control Module Connector End Views for the 2.2L engine |
| • | Powertrain Control Module Connector End Views for the 3.5L engine |
| • | Engine Control Module Connector End Views for the 3.9L engine |
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 PCM/ECM EVAP Data List should indicate a value at or greater than 98 percent.
Circuit/System Testing
- With the ignition OFF, disconnect C413.
- With the ignition ON, install a scan tool and observe the Fuel Tank Level Remaining parameter in the PCM/ECM EVAP Data List.
| ⇒ | If the Fuel Tank Level Remaining parameter indicates a value less than 4 percent, check the signal circuit of the fuel level sensor for a short to ground between C413 and the fuel level sensor. |
| ⇒ | If the fuel level sensor circuit tests normal between C413 and the fuel level sensor, replace the fuel level sensor. |
| ⇒ | If the Fuel Tank Level Remaining parameter indicates a value greater than 4 percent, check the signal circuit of the fuel level sensor circuit for a short to ground between C413 and the PCM/ECM. |
| ⇒ | If the fuel level sensor circuit tests normal between C413 and the PCM/ECM replace the PCM/ECM |
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Fuel Level Sensor Replacement for the 2.2L engine |
| • | Fuel Sender Assembly Replacement for the 3.5L engine |
| • | Fuel Level Sensor Replacement for the 3.9L engine |
| • | Control Module References for the PCM/ECM replacement, setup, and programming |
