P0622

dabunk

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MAKE:chevy
MODEL:3500 van
YEAR:2009
MILES:143K
ENGINE
:6.0 gas
DESCRIBE ISSUE....Replaced alternator and battery and checked all connections code keeps coming back. Any suggestions
 

EricC

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Here's a charging system schematic. Did you check the fusible link between the battery and generator? Gotta run right now, post back if you need more.

Also

Circuit/System Description

The engine control module (ECM) uses the generator field duty cycle signal circuit to monitor the duty cycle of the generator. The generator field duty cycle signal circuit connects to high side of the field windings in the generator. A pulse width modulated (PWM) high side driver in the voltage regulator turns the field windings ON and OFF. The ECM uses the PWM signal input to determine the generator load on the engine. This allows the ECM to adjust the idle speed to compensate for high electrical loads. The ECM monitors the status of the generator field duty cycle signal circuit. When the Ignition is in the RUN position and the engine is OFF, the ECM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5-95 percent.

Conditions for Running the DTC



  • No generator, crankshaft position (CKP) sensor, or camshaft (CMP) sensor DTCs are set.
  • Ignition ON engine OFF, for the Ignition ON test.
  • Engine running, engine speed less than 3,000 RPM for the RUN test.
Conditions for Setting the DTC

  • Ignition ON engine OFF, the ECM detects a PWM signal that is greater than 65 percent for 5 seconds.
  • Engine running, the ECM detects a PWM signal that is less than 5 percent for 15 seconds.
Action Taken When the DTC Sets

DTC P0622 is a C type DTC.

Conditions for Clearing the DTC

DTC P0622 is a C type DTC.

Reference Information
Schematic Reference

Starting and Charging Schematics (See: Diagrams\Electrical\Starting and Charging\System Diagram)
Connector End View Reference

Component Connector End Views (See: Diagrams\Connector Views)
Description and Operation

Charging System Description and Operation (See: Starting and Charging\Charging System\Description and Operation)
Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (See: Testing and Inspection\Programming and Relearning) for scan tool information

Circuit/System Verification

With the scan tool installed, ignition ON and the Engine running, observe the scan tool ECM GEN-F Terminal Signal parameter. The parameter should read between 5 and 95 percent.

Circuit/System Testing

  1. Verify that a test lamp illuminates between the generator output B+ circuit terminal B X2 and ground.
¤ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  1. Ignition OFF, disconnect the harness connector X1 at the generator.
  2. Ignition ON, verify the scan tool ECM GEN-F Terminal Signal parameter displays less than 5 percent.
¤ If greater than the specified range, test the signal circuit terminal C X1 for a short to voltage. If the circuit tests normal, replace the ECM.
  1. Install a 3A fused jumper wire between B+ and the signal circuit.
  2. Verify the scan tool ECM GEN-F Terminal Signal parameter displays greater than 95 percent.
¤ If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  1. If the circuit tests normal replace the generator.
 

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kev2

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problem is with F terminal wire or connector... I will try to find a diagram to add,
might check wire for open...while I ck

never mind
EricC did all that while I typed
Keep us posted
 
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