FixVault
Home › Chevrolet › 2017 › Spark LS, Automatic CVT Trans › Repair and Diagnosis › External Pages › Different car › Section 61 (Engine Cooling System) › Diagnostic Information and Procedures › DTC P112F › Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
  1. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the B203 Engine Coolant Radiator Temperature Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the low reference terminal 2 and ground.
    • If 5 Ω or greater 
    1. Vehicle OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the low reference 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.
    • Go to next step: If less than 5 Ω 
  3. Vehicle in Service Mode.
  4. Verify the scan tool Radiator Coolant Temperature Sensor parameter is colder than -39°C (-38°F).
    • If warmer than -39°C (-38°F) 
    1. Vehicle OFF, disconnect the harness connector at the K20 Engine 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, replace the K20 Engine Control Module.
    • Go to next step: If colder than -39°C (-38°F) 
  5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2, Vehicle in Service Mode.
  6. Verify the scan tool Radiator Coolant Temperature Sensor parameter is warmer than 140°C (284°F).
    • If colder than the 140°C (284°F) 
    1. Vehicle OFF, disconnect the harness connector at the K20 Engine Control Module, Vehicle in Service Mode.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    3. Vehicle OFF
    4. Test for less than 2 Ω in the signal 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.
    • Go to next step: If warmer than 140°C (284°F) 
  7. Test or replace the B203 Engine Coolant Radiator Temperature Sensor.
About FixVault