Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Search for P2500 GMC Questions and Answers: Search here →
What is the Cost to Diagnose the Code?
Labor: 1.0
The cost to diagnose the P2500 GMC code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.
What are Code Possible Symptoms?
Engine Light ON (or Service Engine Soon Warning Light)
What Does the P2500 GMC Code Mean?
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 ECM turns ON the high-side driver, the voltage regulator turns ON the field circuit. When 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. With the engine running, ECM should detect a high generator turn ON signal circuit. The Diagnostic Trouble Code (DTC) will set when the ECM detects a low signal voltage on the generator turn ON signal circuit for at least 15 seconds.
P2500 GMC Code - Low Signal Voltage On Generator Turn ON Signal Circuit