Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Test Procedure
- DL1 CHECK FOR DTCS
Are DTCs P1022, P1023, P2C3A, or P2C3B present?
Yes No GO to DL2. RETURN to SYMPTOM CHARTS for further direction. - DL2 CHECK THE RESISTANCE OF THE CHT2 SENSOR WITH THE ENGINE OFF NOTE: Refer to the chart at the beginning of this test for the resistance specifications.
- Ignition OFF.
- CHT2 Sensor connector disconnected.
- Measure the resistance between:
(+) CHT2 Sensor Connector, Component Side (-) CHT2 Sensor Connector, Component Side CHT2 SIGRTN
Is the resistance within specification?
Yes No GO to DL3. INSTALL a new CHT2 sensor.
REFER to the Electronic Engine Controls article.
CLEAR the DTCs. REPEAT the self-test. - DL3 CHECK FOR AN OPEN CIRCUIT
- Ignition OFF.
- PCM-E connector disconnected.
- For F150,
- PCM-T connector disconnected.
- Measure the resistance between:
(+) PCM-T Connector, Harness Side (-) CHT2 Sensor Connector, Harness Side CHT2 - Pin 40 CHT2 - Measure the resistance between:
(+) PCM-E Connector, Harness Side (-) CHT2 Sensor Connector, Harness Side SIGRTN SIGRTN - For all others,
- Measure the resistance between:
(+) PCM-E Connector, Harness Side (-) CHT2 Sensor Connector, Harness Side CHT2 CHT2 SIGRTN SIGRTN
Are the resistances less than 5 ohms?
Yes No GO to DL4. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - DL4 CHECK FOR A SHORT TO GROUND
Are the resistances greater than 10K ohms?
Yes No GO to DL5. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. - DL5 CHECK FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) CHT2 Sensor Connector, Harness Side (-) CHT2 Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to DL6. - DL6 CHECK THE RESISTANCE OF THE CHT SENSOR NOTE: Refer to the chart at the beginning of this test for the resistance specifications.
- Ignition OFF.
- CHT2 Sensor connector connected.
- PCM-E connector connected.
- PCM-T connector connected.
- Run the engine until the engine temperature stabilizes.
- Ignition OFF.
- CHT2 Sensor connector disconnected.
- Measure the resistance between:
(+) CHT2 Sensor Connector, Component Side (-) CHT2 Sensor Connector, Component Side CHT2 SIGRTN
Is the resistance within specification?
Yes No GO to DL7. INSTALL a new CHT2 sensor.
REFER to the Electronic Engine Controls article.
CLEAR the DTCs. REPEAT the self-test. - DL7 CHECK THE CHT2 SENSOR
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) CHT2 Sensor Connector, Harness Side (-) CHT2 Sensor Connector, Harness Side CHT2 SIGRTN - Observe the digital multi meter (DMM) for an indication of a concern while shaking, wiggling, and bending the CHT2 circuit between the CHT2 and the PCM. Note that voltage changes suddenly when a concern is detected.
Is a concern present?
Yes No REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test.GO to DL8. - DL8 TEMPERATURE SENSOR CORRELATION NOTE: Cold soak the vehicle at ambient temperature for at least 6 hours while not in direct sunlight.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.