LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2015 >> Regal GS, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 6 (Manual Transaxle - F40) >> Diagnostic Information and Procedures >> DTC P0502 or P0503: Vehicle Speed Sensor >> 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 B115 Vehicle Speed 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. Disconnect the X2 harness connector at the K20 Engine Control Module.
    2. Test for less than 2Ω in the circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K20 Engine Control Module.
    • If less than 10Ω 
  3. Ignition ON.
  4. Test for 4.8-5.2V between the 5V reference circuit terminal 1 and ground.
    • If less than 4.8V 
    1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine 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 K20 Engine Control Module.
    • If greater than 5.2V 
    1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine 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 K20 Engine Control Module.
    • If between 4.8-5.2V 
  5. Ignition OFF, connect the test leads of the J-38522-A vehicle signal generator as follows:
    • Red test lead to the signal circuit terminal 3 at the B115 Vehicle Speed Sensor wire harness connector.
    • Black test lead to ground at the transmission case.
    • Double black power and ground lead wire to B+ and ground.
  6. Set and adjust the J-38522-A vehicle signal generator to the following switch positions:
    • Signal switch to 5 V.
    • Frequency switch to 600 Hz.
    • Duty cycle switch to 50% or normal position.
  7. Ignition ON.
  8. Verify the scan tool Vehicle Speed Sensor parameter displays between 41-51 km/h (25-32 mph).
    • If the vehicle speed sensor parameter is not within the specified range 
    1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal 3 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 K20 Engine Control Module.
    • If the vehicle speed sensor parameter is within the specified range 
  9. Replace the B115 Vehicle Speed Sensor.
scientia non olet · About LEMON Manuals