Circuit/System Testing

• If less than 1.7 V 

1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Signal circuit terminal 4 & Ground
   • If less than infinite resistance - Repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
4. Test for less than 2 ohms between the test points: Signal circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Replace the component: K20 Engine Control Module

• If greater than 3.0 V 

1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points: Signal circuit terminal 4 @ Component harness & Ground
   • If 1 V or greater - Repair the short to voltage on the circuit.
   • If less than 1 V - Replace the component: K20 Engine Control Module

• Go to next step: If between 1.7 and 3 V 

• If 1.7 V or less 

1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points: Signal circuit terminal 3 @ Component harness & Ground
   • If less than infinite resistance - Repair the short to ground on the circuit.
   • If infinite resistance - Replace the component: K20 Engine Control Module

• Go to next step: If greater than 1.7 V 

• If greater than 0.0 V 

1. Ignition/Vehicle - Off & Remove - Jumper wire (s)
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points: Signal circuit terminal 3 @ Component harness & Ground
   • If 1 V or greater - Repair the short to voltage on the circuit.
   • Go to next step: If less than 1 V
5. Ignition/Vehicle - Off
6. Test for less than 2 ohms between the test points: Signal circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Replace the component: K20 Engine Control Module

• Go to next step: If 0.0 V 

• B52 Heated Oxygen Sensor - Water intrusion @ Harness Connector
• Coolant consumption - Refer to: Loss of Coolant (LSY)
• Engine - Vacuum leak
• Engine Oil - Oil consumption - Refer to: Oil Consumption Diagnosis
• Evaporative Emission Canister - Saturated with fuel
• Exhaust System - Cracked/Leaking/Loose Clamps/Missing components/Restricted - Refer to: Symptoms - Engine Exhaust
• Fuel - Contaminated/Poor Quality - Refer to: Alcohol/Contaminants-in-Fuel Diagnosis
• Fuel Injectors - Restricted/Stuck - Refer to: Fuel Injector Diagnosis
• Fuel Pressure - High/Low - Refer to: Fuel System Diagnosis
• Vacuum leak @ Engine - Oil Level Indicator and Tube /Oil Filler Cap

• If a condition exists 

  Repair or replace as necessary

• Go to next step: If no condition exists 

Verify the DTC does not set.

• If the DTC sets 

  Replace the appropriate component: B52 Heated Oxygen Sensor

• Go to next step: If the DTC is not set