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 P2501: Generator L-Terminal Circuit High VoltageDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Generator F-Terminal | P02500 | P2500 | P2501 | -- |
Circuit/System Description
The engine control module (ECM) uses the generator turn on signal circuit to control the load of the generator on the engine. A high side driver in the ECM applies a voltage to the voltage regulator. This signals the voltage regulator to turn the field circuit ON and OFF. When the ECM turns ON the high side driver, the voltage regulator turns ON the field circuit. When the ECM turns OFF the high side driver, the voltage regulator turns OFF the field circuit.
The ECM monitors the state of the generator turn on signal circuit. The ECM should detect a low generator turn on signal circuit voltage when the Ignition is ON and the engine is OFF, or when the charging system malfunctions. If the ECM detects a high generator turn on signal circuit voltage, DTC P2501 will set.
Conditions for Running the DTC
| • | No generator, crankshaft position (CKP) sensors, or camshaft position (CMP) sensor DTCs are set. |
| • | The ignition is in the ON position. |
| • | The engine is not running. |
Conditions for Setting the DTC
The ECM detects a high signal voltage on the generator turn on signal circuit for at least 5 seconds.
Action Taken When the DTC Sets
DTC P2501 is a C type DTC.
Conditions for Clearing the DTC
DTC P2501 is a C type DTC.
Reference Information
Schematic Reference
Starting and Charging Schematics
Connector End View Reference
Description and Operation
Charging System Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the generator.
- Ignition ON, test for less than 1 volt between the generator turn on signal circuit terminal and ground.
- If the circuit tests normal, test or replace the generator.
| ⇒ | If greater than the specified range, test the generator turn on signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM replacement, setup, and programming |
