Power Solutions International

DTC 642

UnclassifiedElectrical

What This Code Means

Malfunction Indicator Light (MIL) ON during active fault; Adaptive Learn disabled; 5 volt reference voltage lower than 4.60 volts; DST displays MAP voltage less than the limit defined in calibration with the engine idling; MIL ON during active fault; Adaptive Learn disabled during active fault

Possible Causes

  • •Sensors or fuel system components are overloaded, shorted, or out of specification
  • •Poor connection at sensor
  • •Faulty MAP sensor
  • •Intermittent Problem
  • •5 volt reference voltage lower than 4.60 volts
  • •External 5 volt supply overloaded, shorted, or out of specification

Suggested Actions

  1. 1Perform the On-Board (OBD) System Check
  2. 2Troubleshoot DTC 642 or DTC 643 first if present
  3. 3Using a DMM, measure the voltage potential across 5ref1 and 5V rtn1 at connector to check if >4.7 VDC
  4. 4Jumper the MAP circuit to Vref (5 VDC) in connector on harness and check if DST displays MAP voltage of 4.7 VDC or greater
  5. 5Key off, disconnect wire harness header from ECM, carefully remove yellow lock from header at device output terminal, and check resistance between MAP input at ECM header and signal at device (ensuring no probe or object is inserted into terminals to prevent spreading pins)

Related Power Solutions International Fault Codes

DTC 643DTC 562DTC 160 2DTC 154DTC 122DTC 118DTC 113DTC 107891030112122643
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