LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2015 >> Regal GS, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Controls And Fuel - 2.4L - DTC P0628 To DTC P2635 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC P0641 or P06A6: 5V Reference (Chassis Control Module) >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B47 Fuel Pressure Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10Ω between the low reference circuit terminal 2 and ground.
    • If 10Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
    2. Test for less than 2Ω in the low reference circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K38 Chassis Control Module.
    • If less than 10Ω 
  3. Ignition ON.
  4. Test for 4.8-5.2V between the 5V reference circuit terminal 3 and ground.
    • If less than 4.8V 
    1. Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
    2. Test for infinite resistance between the 5V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the 5V reference circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K38 Chassis Control Module.
    • If greater than 5.2V 
    1. Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module, ignition ON.
    2. Test for less than 1V between the 5V reference circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K38 Chassis Control Module.
    • If between 4.8-5.2V 
  5. Verify the scan tool Fuel Pressure Sensor Voltage parameter is less than 1V.
    • If 1V or greater 
    1. Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module, ignition ON.
    2. Test for less than 1V between the signal circuit terminal 1 and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K38 Chassis Control Module.
    • If less than 1V 
  6. Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5V reference circuit terminal 3, wait 15 seconds.
  7. Verify the scan tool Fuel Pressure Sensor Voltage parameter is greater than 4.8V.
    • If 4.8V or less 
    1. Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
    2. Test for infinite resistance between the signal circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K38 Chassis Control Module.
    • If greater than 4.8V 
  8. Test or replace the B47 Fuel Pressure Sensor.
scientia non olet · About LEMON Manuals