Pinpoint Test A: Electronic Engine Controls Pinpoint Test

1. A1: PERFORMANCE CHECK OF HEATED OXYGEN SENSOR(S) (HO2S) 

   TEST CONDITIONS 

   DETAILS/RESULTS/ACTIONS 

   NOTE:

   • Refer to the Heated Oxygen Sensor (HO2S) location  article for information on Heated Oxygen Sensor (HO2S) locations
   • Oxygen sensors will become functional at different times, depending on their location within the exhaust system and the previous drive cycles
   1. Refer to the Heated Oxygen Sensor (HO2S) location  and Drive Cycle  articles for information on Heated Oxygen Sensor (HO2S) activation requirements and drive cycles
      NOTE: Pre catalyst oxygen sensor - Signal displayed in mA - Signal changes either side of 0mA as fueling changes from lean to rich
   2. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Current Bank 1 - sensor 1 (low res)
   3. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Current Bank 2 - sensor 1 (low res)
      NOTE: Mid and post catalyst oxygen sensor - Signal displayed in Volts - Signal changes between 0 and 1 volt as fueling switches from lean to rich
   4. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Output Voltage Bank 1 - sensor 3
   5. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Output Voltage Bank 1 - sensor 2
   6. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Output Voltage Bank 2 - sensor 2
   7. Using the manufacturer approved diagnostic system check datalogger signal Oxygen Sensor Output Voltage Bank 2 - sensor 3
   8. View the output signals for each Heated Oxygen Sensor (HO2S). Once active each sensor can be seen reacting to changes in engine speed/load

      Observe the oxygen sensor signal responsible for the DTC. Is the sensor functioning correctly?

      Yes 

      No failure is found. Clear DTCs and perform road test to confirm no fault is present. Refer to the Heated Oxygen Sensor (HO2S) location  and Drive Cycle  articles for information on Heated Oxygen Sensor (HO2S) activation requirements and drive cycles

      No 

      Proceed to the next step

2. A2: ELECTRICAL CHECK OF HEATED OXYGEN SENSOR(S) (HO2S) HEATER POWER SUPPLY 

   TEST CONDITIONS 

   DETAILS/RESULTS/ACTIONS 

   NOTE:

   • Refer to the Heated Oxygen Sensor (HO2S) location  article for information on Heated Oxygen Sensor (HO2S) locations
   • Carry out the following electrical checks ONLY  on the sensor(s) with the related DTC(s) logged
   1. Refer to the electrical circuit diagrams and check the heater power supply
   2. Switch ignition OFF
   3. Disconnect Heated Oxygen Sensor (HO2S) (with the related DTC(s) logged)
   4. Switch ignition ON
   5. Pre catalyst oxygen sensor.  Measure the voltage between pin 4 and battery ground
   6. Mid and post catalyst oxygen sensor.  Measure the voltage between pin 1 and battery ground

      Is the measured voltage between 11 and 14 volts?

      Yes 

      Proceed to the next step

      No 

      Check for fuse failure

      Check connectors for signs of water ingress, and pins for damage and/or corrosion

      Check for vehicle harness failure - Wiring integrity short circuit to ground, short circuit to power, open circuit, high resistance

3. A3: ELECTRICAL CHECK OF HEATED OXYGEN SENSOR(S) (HO2S) HEATER RESISTANCE 

TEST CONDITIONS 

DETAILS/RESULTS/ACTIONS 

1. Refer to the electrical circuit diagrams and check the heater resistance
2. Switch ignition OFF
3. Ensure the Heated Oxygen Sensor (HO2S) connector is disconnected
4. Pre catalyst oxygen sensor.  Measure the resistance of the sensor between pin 4 and pin 3
5. Mid and post catalyst oxygen sensor.  Measure the resistance of the sensor between pin 1 and pin 2

   Is the measured resistance between 1 and 15 Ohms?

   Yes 

   Check connectors for signs of water ingress, and pins for damage and/or corrosion

   Check for vehicle harness failure - Wiring integrity short circuit to ground, short circuit to power, open circuit, high resistance

   No 

   Install a new Heated Oxygen Sensor (HO2S) component