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HOMESERVICE MANUALSMERCURY2009MOUNTAINEER 4.6 8, RWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - PINPOINT TEST DL: CYLINDER HEAD TEMPERATURE (CHT) SENSOR THROUGH PINPOINT TEST DY: ENGINE OIL TEMPERATURE (EOT) SENSOR - (EXCEPT DIESEL & HYBRID)PINPOINT TEST DY: ENGINE OIL TEMPERATURE (EOT) SENSORINTRODUCTION
2009 Mercury Mountaineer 4.6 8, RWD

Pinpoint Test DY: Engine Oil Temperature (EOT) Sensor: Introduction

2009 Mercury Mountaineer 4.6 8, RWDSECTION Introduction

This pinpoint test is intended to diagnose the following:

  • engine oil temperature (EOT) sensor (12A648)
  • harness circuits: EOT and SIGRTN
  • powertrain control module (PCM) (12A650)

Engine oil temperature must be greater than 10°C (50°F) to pass the KOEO self-test and greater than 66°C (150°F) to pass the KOER self-test.

Voltage values calculated for VREF = 5 volts. These values can vary by 15% due to sensor and VREF variations.

Fig 1: Temperature Sensor Voltage And Resistance Characteristic Graph
G06053965Courtesy of FORD MOTOR CO.
TEMPERATURE SENSOR VOLTAGE AND RESISTANCE SPECIFICATIONS

Temperature Temperature Sensor Values
°C °F Voltage Resistance (K ohms)
120 248 0.28 1.18
110 230 0.36 1.55
100 212 0.47 2.07
90 194 0.61 2.80
80 176 0.80 3.84
70 158 1.05 5.37
60 140 1.37 7.70
50 122 1.77 10.97
40 104 2.23 16.15
30 86 2.74 24.27
20 68 3.26 37.30
10 50 3.73 58.75
0 32 4.14 95.85
-10 14 4.45 160.31
Fig 2: Engine Oil Temperature (EOT) Sensor Connector
G06053997Courtesy of FORD MOTOR CO.

For PCM connector views or reference values, refer to REFERENCE VALUES .

POWERTRAIN CONTROL MODULE (PCM) CONNECTOR

Connector Pin Circuit
170 Pin E58
B35
E57
E27		 SIGRTN
VPWR
VREF
EOT
RENDER: 1.0x

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.