LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2018 >> Escalade Base, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 11 (Engine Controls And Fuel - 6.0L (L96) - DTC P0351 To DTC P2636 And Diagnostic Information And Procedures) >> Diagnostic Information And Procedures >> DTC P2632, P2633, P2634: Fuel Transfer Pump Relay Control Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, all vehicle systems OFF, disconnect the Secondary Fuel Pump Relay. It may take up to 2 min for all vehicle systems to power down.
  2. Ignition ON.
  3. Verify a test lamp illuminates between the ground circuit terminal 85 and B+.
    • If the test lamp does not illuminate 
    1. Ignition OFF, remove the test lamp.
    2. Test for less than 2 Ω on the ground circuit end to end.
      • If greater than 2 Ω, repair the open/high resistance in the circuit.
      • If 2 Ω or less, repair the open/high resistance in the ground connection.
    • Go to next step: If the test lamp illuminates 
  4. Connect a test lamp between the ground circuit terminal 85 and the control circuit terminal 86, Ignition ON.
  5. Verify the test lamp turns ON and OFF when commanding the Fuel Pump 2 Relay On and Off with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If the test lamp turns ON and OFF 
  6. Test or replace the Secondary Fuel Pump Relay.
scientia non olet · About LEMON Manuals