Test L: Engine Oil Temperature (EOT) Sensor
PINPOINT TEST L: ENGINE OIL TEMPERATURE (EOT) SENSORFlow Chart (Part 1):
Flow Chart (Part 2):
WARNING: Be aware of moving vehicle components and heat. Failure to follow these instructions may result in personal injury.
This pinpoint test is intended to diagnose the following:
- EOT sensor (12A648)
- harness circuits: EOT and SIGRTN
- powertrain control module (PCM) (12A650)
Temperature Vs. Resistance Values (Approximate):
EOT Sensor Connector
EOT Sensor Connector:
PCM Connector
PCM Connector:
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L1 : PRELIMINARY DIAGNOSIS FOR DIAGNOSTIC TROUBLE CODES (DTCS) P0196, P0197, P0198, P1184, OR P0298
- Carry out a visual inspection.
- Retrieve and record any continuous and on-demand DTCs
- Record the freeze frame data.
- Clear the DTCs.
- Carry out the KOEO self-test. Quick Test Description
- Carry out the KOER self-test. Quick Test Description
- Are DTCs P0196, P0197, P0198, P1184, or P0298 present?
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L2 : DTC P0196
- DTC P0196 indicates that an EOT sensor range/performance concern has been detected. P0196 is set when the vehicle has been driven above 1,250 RPM and 12 mg/stroke mass fuel desired (MFDES) without the EOT sensor signal increasing above 50°C (122°F). The time to set the concern is dependent on the EOT and intake air temperature (IAT) temperatures and can vary between 15 and 45 minutes.
Possible Causes:
- EOT sensor
- EOT sensor circuitry
- thermostat
- PCM
- Inspect the EOT sensor circuitry at the sensor and PCM. Inspect for damaged, loose or pushed-out pins, and loose or poorly crimped wires.
- Are all connectors and terminals OK?
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L3 : CHECK FOR DTCS
- Carry out the KOEO on-demand self-test. Quick Test Description
- Are any other DTCs present?
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L4 : CHECK THE EOT SENSOR OPERATION
NOTE: Verify no accessories are in use (engine block or oil heaters)
- Clear all the DTCs.
- Cold soak the vehicle at ambient temperature for at least 10 hours.
- Ignition ON, engine OFF.
- Access the PCM and monitor the EOT PID.
- Access the PCM and monitor the RPM PID.
- Access the PCM and monitor the MFDES PID.
- Record the EOT sensor temperature value.
- Drive the vehicle at an engine speed greater than 1,800 RPM and 15 mg/stroke MFDES for at least 15 minutes. Select the appropriate gear to achieve the operating conditions.
- Does the EOT temperature value change by at least 6°C (10°F) from the ignition ON value recorded?
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L5 : CHECK THE COOLING SYSTEM
- Drive the vehicle an additional 15 minutes at an engine speed greater than 1,800 RPM and 15 mg/stroke MFDES.
- Does the EOT temperature reading increase above 50°C (122°F)?
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L6 : CHECK THE PCM FOR DTCS
- Ignition ON, engine OFF.
- Retrieve the continuous memory DTCs.
- Is DTC P0196 present?
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L7 : DTC P0197
NOTE: Refer to the PCM and component connector pin numbers at the beginning of this pinpoint test.
- Possible causes:
- EOT signal circuit short to ground
- EOT sensor
- PCM
- EOT electrical connections
- Ignition OFF.
- EOT Sensor connector disconnected.
- The EOT sensor is disconnected to simulate the opposite DTC.
- Check for damaged, pushed-out, or corroded pins.
- Ignition ON, engine OFF.
- Carry out the KOEO self-test. Quick Test Description
- Is DTC P0198 present?
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L8 : CHECK THE EOT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
- Is the resistance greater than 10 kOhm?
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L9 : DTC P0198
- Possible causes:
- EOT signal circuit open or short to voltage
- signal return circuit open
- poor connections
- EOT sensor
- PCM
- EOT Sensor connector disconnected.
- PCM connector disconnected.
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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L10 : SIMULATE THE OPPOSITE DTC
- PCM connector connected.
- Ignition ON, engine OFF.
- Connect a 5 amp fused jumper wire between the following:
- Carry out the on-demand self-test.
- Is DTC P0197 present?
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L11 : CHECK THE SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
- Is the voltage less than 0.2 V?
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L12 : CHECK THE SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between:
- Is the resistance less than 5 Ohm?
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L13 : DTC P1184
- DTC P1184 indicates that the engine oil temperature is not within the required range to carry out the KOER Cylinder Contribution self-test. The engine oil temperature must be between 20°C (68°F) and 117°C (242°F)
Possible Causes:
- engine not fully warmed up
- low oil level
- cooling system failure
- EOT sensor
- thermostat
- EOT sensor circuit
- Verify no KOEO DTCs are present.
- Drive the vehicle until the thermostat opens.
- Engine at normal operating temperature.
- Carry out the KOER Cylinder Contribution self-test.
- Is DTC P1184 present?
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L14 : EOT SENSOR CHECK
- Ignition ON, engine OFF.
- Engine at normal operating temperature.
- Access the PCM and monitor the EOT PID.
- Monitor the EOT PID while tapping on the EOT sensor.
- Does the EOT value fluctuate or decrease below 20°C (68°F) (3.82 volts)?
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L15 : CHECK THE VEHICLE HARNESS
- Monitor the PID while carrying out the following:
- Grasp the vehicle harness close to the EOT sensor connector.
- Wiggle and shake vehicle harness while working toward PCM.
- Does the EOT PID value fluctuate?
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L16 : CHECK THE PCM AND VEHICLE HARNESS CONNECTORS
- Ignition OFF.
- EOT Sensor connector disconnected.
- PCM connector disconnected.
- Inspect for damaged, loose, or pushed-out pins.
- Are connectors and terminals OK?
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L17 : CHECK FOR A BIASED EOT SENSOR
NOTE: Verify no accessories are in use (engine block or oil heaters)
- Allow the vehicle to sit overnight.
- Ignition ON, engine OFF.
- Access the PCM and monitor the EOT PID.
- Access the PCM and monitor the IAT PID.
- Are the EOT and IAT PID values within 6°C (11°F)?
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L18 : DTC P0298
- DTC P0298 indicates that an EOT sensor range/performance concern has been detected. P0298 is set when the vehicle has been operating at less than 1,000 RPM and less than 20 mg/stroke mass fuel desired (MFDES) with the EOT sensor signal reading above 110°C (230°F). The time to set the concern is dependent on the EOT and IAT temperatures and can vary between 15 and 45 minutes.
Possible Causes:
- EOT sensor
- EOT sensor circuitry
- cooling system
- thermostat
- PCM
- Inspect the EOT sensor circuitry at the sensor and PCM.
- Inspect for damaged, loose or pushed-out pins, and loose or poorly crimped wires.
- Are all connectors and terminals OK?
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L19 : CHECK THE COOLING SYSTEM
- Check the coolant system for correct level.
- Check the radiator for correct operation. Verify there are no airflow obstructions across the radiator core and that the radiator core is not plugged.
- Verify the correct cooling fan/clutch operation.
- Verify the correct thermostat operation.
- Is the coolant system OK?
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L20 : CHECK FOR EOT SENSOR DTCS
- Carry out the KOEO self-test. Quick Test Description
- Are other DTCs present?
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L21 : CHECK THE EOT SENSOR OPERATION
NOTE: Verify no accessories are in use (engine block or oil heaters)
- Clear the continuous DTCs.
- Cold soak the vehicle at ambient temperature for at least 8 hours.
- Ignition ON, engine OFF.
- Access the PCM and monitor the EOT PID.
- Is the EOT sensor PID equal to ambient temperature?
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L22 : CONFIRM THE PCM CONCERN
- Operate the engine for approximately 15 to 20 minutes.
- Retrieve the continuous memory DTCs.
- Is DTC P0298 present?
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L23 : CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
