Sierra 1500 2WD V6-4.3L (2008)
Pedal Positioning System: Symptom Related Diagnostic Procedures
Symptoms - Adjustable Pedals
Symptoms - Adjustable Pedals
Important: The following steps must be completed before using the symptom table.
1. If the vehicle is equipped with AAB (Memory Driver Convenience Package) perform the Diagnostic System Check - Vehicle, before using the
symptom table in order to verify that all of the following are true:
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There are no DTCs set.
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The control modules can communicate via the serial data link. See: Testing and Inspection/Initial Inspection and Diagnostic
Overview/Diagnostic System Check - Vehicle
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Adjustable Pedals Description and Operation (w/o
Memory) Adjustable Pedals Description and Operation (with Memory).
Visual/Physical Inspection
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Inspect for aftermarket devices which could affect the operation of the adjustable pedal system.
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Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.
See: Testing and Inspection/Component Tests and General Diagnostics
Symptom List
Refer to Adjustable Pedals Inoperative (w/o memory) Adjustable Pedals Inoperative (with memory).
Adjustable Pedals Inoperative (w/o Memory)
Adjustable Pedals Inoperative (w/o memory)
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection/Initial Inspection and
Diagnostic Overview/Diagnostic System Check - Vehicle
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Review Strategy Based Diagnosis for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
Voltage to the adjustable pedal switch is supplied through the park enable relay while in a de-energized state. The park enable relay is controlled by the
body control module (BCM) through a high side drive control circuit and will be energized whenever the ignition is in the accessory, run, or crank
positions and the transmission is in reverse or the cruise control is engaged. The adjustable pedals switch controls the adjustable pedals relay by applying
battery voltage to one of the coils. In an inactive state both of the relay switch contacts are closed to ground and when one of the relay coils is energized
its switch contact is closed to battery voltage.
Circuit/System Testing
1. Disconnect the left instrument panel (I/P) junction block connector C2.
2. Verify that a test lamp illuminates when connected from the park enable relay supply circuit terminal E2 in the harness connector to ground.
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If the test lamp does not illuminate repair the park enable relay supply circuit for an open or short to ground. If the circuit tests normal and the
EAP fuse #73 is open, test the following circuits for a short to ground:
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Switch supply circuit
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Switch signal circuits
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Motor control circuits
3. Disconnect the left I/P junction block connector C1.
4. Connect a DMM from the adjustable pedal switch supply circuit terminal C4 to the forward switch signal circuit in connector C2 terminal G1.
