Circuit/System Testing
WARNING: This page is about a different variant/trim than selected.
- Ignition OFF, disconnect the X1 harness connector at the K115 Reductant Control Module.
- Connect a test lamp between ignition voltage terminal 8 and ground.
- Ignition ON, verify the test lamp illuminates.
- If the test lamp does not illuminate and the fuse is good
- Ignition OFF, remove KR121A Reductant Control Module Relay 1.
- Test for less than 2 Ω between ignition voltage circuit 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 the fuse is open
- Ignition OFF, test for infinite resistance between ignition voltage circuit 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, P20BC, P214F or P21DD
- 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.
- Ignition On, test for 5 - 7.5 V between terminal 9 and Ground
- If less than 5 V
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- Test for infinite resistance between A38 Reductant Pump and Sensor Assembly X2 harness connector terminal 9 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- 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
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- Ignition On, test for greater than 1 V between A38 Reductant Pump ad 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
- Connect a test lamp between heater control circuit terminal 9 and low reference circuit terminal 11.
- 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
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- 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.
- Go to next step: If infinite resistance
- 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, replace the K115 Reductant Control Module.
- If the Test lamp is always ON
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module, ignition ON.
- 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 responds appropriately to the commanded states
- Test or replace the A38 Reductant Pump and Sensor Assembly.
DTCs P20BD, P20BE, P20BF, P20C0, P221C or P221D
- 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.
- Ignition On, test for 5 - 7.5 V between terminal 2 and ground
- If less than 5 V
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- 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.
- Go to next step: If infinite resistance
- 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
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- 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
- Connect a test lamp between heater control circuit terminal 2 and low reference circuit terminal 1.
- 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
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module.
- 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.
- Go to next step: If infinite resistance
- 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, replace the K115 Reductant Control Module.
- If the Test lamp is always ON
- Ignition OFF, disconnect the X2 harness connector at the K115 Reductant Control Module, ignition ON.
- 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 responds appropriately to the commanded states
- Test or replace the E52 Reductant Line Heater.