LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2018 >> Equinox L >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Controls And Fuel - 1.6L (LH7) Diesel - Diagnostic Information And Procedures (P205B - P2BAA) And Symptoms) >> Diagnostic Information And Procedures >> DTC P20B9-P20BF Or P20C0-P20C5: Reductant Heater 1-2 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, disconnect the X1 harness connector at the K115 Reductant Control Module.
  2. Connect a test lamp between ignition voltage terminal 8 and ground.
  3. Ignition ON, verify the test lamp illuminates.
    • If the test lamp does not illuminate and fuse F45UA is good 
    1. Ignition OFF, remove KR121A Reductant Control Module Relay 1.
    2. Test for less than 2 Ω between ignition voltage terminal 8 and relay terminal 30.
    • If 2 Ω or greater, repair the open/high resistance in the circuit
    • If less than 2 Ω, replace the relay
    • If the test lamp does not illuminate and fuse F45UA is open 
    1. Ignition OFF, test for infinite resistance between ignition voltage terminal 8 and ground.
    • if less than infinite resistance, repair the short to ground in the circuit
    • Go to next step: If the test lamp illuminates 

DTCs P20B9, P20BA, P20BB or P20BC

  1. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down, disconnect the harness connector at the A38 Reductant Pump and Sensor Assembly.
  2. Ignition On, test for 5 - 7.5 V between terminal 9 and Ground
    • If less than 5 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Test for infinite resistance between A38 Reductant Pump and Sensor Assembly harness connector terminal 9 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 between A38 Reductant Pump and Sensor Assembly harness connector terminal 9 and K115 Reductant Control Module X2 harness connector terminal 11.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K115 Reductant Control Module.
    • If greater than 7.5 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Ignition On, test for greater than 1 V between A38 Reductant Pump and Sensor Assembly harness connector terminal 9 and ground
      • If greater than 1 V repair the short to voltage in the circuit
      • If less than 1 V replace the K115 Reductant Control Module
    • Go to next step: If between 5 and 7.5 V 
  3. Connect a test lamp between heater control circuit terminal 9 and low reference circuit terminal 11.
  4. Ignition ON, verify the test lamp turns ON for several seconds while commanding Reductant Heater 1 ON with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Test for infinite resistance between the A38 Reductant Pump and Sensor Assembly harness connector terminal 11 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 between A38 Reductant Pump and Sensor Assembly harness connector terminal 11 and K115 Reductant Control Module X2 harness connector terminal 4.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω
    4. Test for less than 1.0 V between the A38 Reductant Pump and Sensor Assembly harness connector terminal 11 and ground.
      • If 1.0 V or greater, repair the short to voltage in the circuit.
      • If less than 1.0 V, replace the K115 Reductant Control Module.
    • Go to next step: If the Test lamp turns ON and OFF 
  5. Test or replace the A38 Reductant Pump and Sensor Assembly.

DTCs P20BD, P20BE, P20BF, P20C0

  1. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down, disconnect the harness connector at the E52 Reductant Line Heater.
  2. Ignition On, test for 5 - 7.5 V between terminal 2 and ground
    • If less than 5 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Test for infinite resistance between E52 Reductant Line Heater harness connector terminal 2 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 between E52 Reductant Line Heater harness connector terminal 2 and K115 Reductant Control Module X2 harness connector terminal 7.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K115 Reductant Control Module.
    • If greater than 7.5 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Ignition On, test for greater than 1 V between E52 Reductant Line Heater harness connector terminal 2 and ground
      • If greater than 1 V repair the short to voltage in the circuit
      • If less than 1 V replace the K115 Reductant Control Module
    • Go to next step: If between 5 and 7.5 V 
  3. Connect a test lamp between heater control circuit terminal 2 and low reference circuit terminal 1.
  4. Ignition ON, verify the test lamp turns ON for several seconds while commanding Reductant Heater 2 ON with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
    2. Test for infinite resistance between the E52 Reductant Line Heater harness connector 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 2 Ω between E52 Reductant Line Heater harness connector terminal 1 and K115 Reductant Control Module X2 harness connector terminal 20.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω
    4. Test for less than 1.0 V between the E52 Reductant Line Heater harness connector terminal 1 and ground.
      • If 1.0 V or greater, repair the short to voltage in the circuit.
      • If less than 1.0 V, replace the K115 Reductant Control Module.
    • Go to next step: If the Test lamp turns ON and OFF 
  5. Test or replace the E52 Reductant Line Heater.
scientia non olet · About LEMON Manuals