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Chevrolet Silverado / GMC Sierra. Manual - part 2422
Instrument Cluster Schematics
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector X2 at the ECM.
2. Ignition ON, verify that the wait to start indicator is OFF.
If not the specified value, test the wait to start indicator control signal circuit terminal
16 for a short to ground. If the circuit tests normal, replace the instrument panel cluster
(IPC).
3. Install a 3-amp fused jumper between the wait to start control signal circuit terminal 16 and
ground. Verify that the wait to start indicator is ON.
If not the specified value, test the wait to start indicator control signal circuit terminal
16 for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the IPC.
4. If all circuits test normal, replace the ECM.
Repair Procedures
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for the ECM or IPC replacement, setup, and programming
DTC P0461
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Displays and Gages - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P0461
Fuel Level Sensor 1 Performance
Diagnostic Fault Information
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 instrument cluster in order to control the fuel gage. The fuel information
is also used for misfire and evaporative emission (EVAP) diagnostics.
This diagnostic tests for a stuck fuel level sensor signal. The ECM sets this DTC if the fuel level
sensor signal appears to be stuck based on a lack of signal variation expected during normal
operation.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
Circuit
Short to
Ground
High
Resistance
Open
Short to
Voltage
Signal
Performance
Fuel Level Sensor Signal
P0462
1
P0463,
P0464
P0463
P0461
Fuel Level Sensor Low
Reference
-
1
P0463,
P0464
P0463
P0461
1. Fuel Gage Inaccurate or Inoperative
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Displays and Gages - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
The ECM detects a change in fuel level less than 10 liters (1.3 gallons) over a distance of 241.4
km (150 miles).
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.
Reference Information
Schematic Reference
Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Instrument Cluster Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for Scan Tool Information
Component Testing
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Displays and Gages - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
1. Ignition OFF, remove the fuel level sender and verify there are no obstructions interfering
with the fuel level sender.
If any interference is present, repair the fuel sender interference.
2. Ignition OFF, disconnect the harness connector at the fuel level sensor.
3. While sweeping the fuel level sensor through its full range of motion, test for a minimum
resistance value of less than 41 ohms and a maximum value greater than 119 ohms between
the signal terminal C and the low reference terminal B.
If not within the specified range, replace the fuel level sensor.
Repair Procedures
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Fuel Level Sensor Replacement (Extended Cab w/26 Gal Tank) or Fuel Level Sensor
Replacement (Regular Cab w/34 Gal Tank) or Fuel Level Sensor Replacement
(Regular Cab w/26 Gal Tank) for the 4.3L engine
Fuel Level Sensor Replacement (15 Reg Cab w/26 gal Tank) or Fuel Level Sensor
Replacement (15 Ext/Crew Cab w/26 gal Tank) or Fuel Level Sensor Replacement
(25 Ext/Crew Cab w/26 gal Tank) or Fuel Level Sensor Replacement (15/25
Reg/Ext/Crew Cab w/34 gal Tank) or Fuel Level Sensor Replacement (35
Reg/Ext/Crew Cab w/34 gal Tank) for the 4.8L, 5.3L, 6.0L, and 6.2L engines
Fuel Level Sensor Replacement (Cab/Chassis - Rear Tank) for the 6.6L engine
Control Module References for ECM replacement, setup, and programming
DTC P0462
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P0462
Fuel Level Sensor 1 Low Voltage
Diagnostic Fault Information
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Displays and Gages - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
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