LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 1996 >> Probe Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 2.0L >> Circuit Tests >> Circuit Test Db - Engine Fuel Temperature (Eft) Sensor >> Diagnostic Aids
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Aids

Perform this test only when directed by QUICK TEST . EFT sensor will operate within the range of -40-248°F (-40-120°C). This circuit test is intended to diagnose the following components and circuits:

Fig 1: EFT Connector Terminals
G95B35932
Fig 2: Injector Pressure (IP) Sensor Connector Terminals
G95C35933
Fig 3: Fuel Rail Components
G95D35934
EFT SENSOR SPECIFICATIONS

Temperature °F (°C) (1) Volts (1) Ohms
50 (10) 3.51 58,750
68 (20) 3.07 27,300
86 (30) 2.60 24,270
104 (40) 2.13 16,150
122 (50) 1.70 10,970
140 (60) 1.33 7700
158 (70) 1.02 5370
176 (80) 0.78 3840
194 (90) 0.60 2800
212 (100) 0.46 2070
248 (120) 0.27 1180
(1) Values may vary by 15 percent.
  1. Step 1) DTC P0183 (EFT A) Or P0188 (EFT B)  This trouble code indicates sensor signal is greater than self-test maximum. Self-test maximum is 4.6 volts. Check for following possible causes:
    • Open circuit in wiring harness.
    • Faulty harness connector.
    • Faulty sensor.
    • Faulty PCM.

    Turn ignition off. Disconnect suspect temperature sensor. Connect a jumper wire between signal circuit (EFT A or EFT B) terminal and SIG RTN terminal at sensor wiring harness connector. With scan tester installed, turn ignition on.

    NOTE: If communication link error is displayed, remove jumper wire and go to step 12).

    Access EFT A or EFT B PID. If the PID is less than 0.2 volt, replace sensor and repeat QUICK TEST . If PID is 0.2 volt or more, remove jumper wire and go to next step.

  2. Step 2) Check Continuity Of Sensor Signal & SIG RTN Circuits  Turn ignition off. Ensure suspect temperature sensor is disconnected. Disconnect PCM 104-pin connector. Check for damaged wiring, and repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 62 (EFT A) or test pin No. 10 (EFT B) at breakout box and SIG RTN terminal at sensor wiring harness connector. Also, measure resistance between test pin No. 91 (SIG RTN) and SIG RTN circuit at sensor wiring harness connector. If both readings are less than 5 ohms, replace PCM, and repeat QUICK TEST. If either reading is 5 ohms or more, repair open circuit and repeat QUICK TEST .
  3. Step 3) Check For Sensor Signal Short To VREF  Turn ignition off. Ensure suspect temperature sensor is disconnected. Disconnect PCM 104-pin connector. Check for damaged wiring, and repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 90 (VREF) and test pin No. 62 (EFT A) or test pin No. 10 (EFT B) at breakout box. If resistance is 10,000 ohms or more, replace PCM and repeat QUICK TEST . If either resistance is less than 10,000 ohms, repair short circuit to VREF and repeat QUICK TEST.
  4. Step 4) DTC P0182 (EFT A) Or P0187 (EFT B)  This trouble code indicates sensor signal is less than self-test minimum. Self-test minimum is 0.2 volts. Check for following possible causes:
    • Wiring harness circuit short to ground.
    • Faulty harness connector.
    • Faulty sensor.
    • Faulty PCM.

    Turn ignition off. Disconnect suspect temperature sensor. With scan tester connected to DLC, turn ignition on. Access EFT A PID or EFT B PID. If the PID is less than 4.2 volt, replace sensor and repeat QUICK TEST . If the PID is 4.2 volt or more, go to next step.

  5. Step 5) Check VREF Circuit Voltage At Injection Pressure (IP) Sensor  Turn ignition off. Disconnect IP sensor wiring harness connector. Turn ignition on. Measure voltage between VREF and SIG RTN at IP sensor wiring harness connector. If voltage is 4-6 volts, connect IP sensor and go to next step. If voltage is not 4-6 volts, go to CIRCUIT TEST C.
  6. Step 6) Check Signal Circuit For Short To Ground  Turn ignition off. Disconnect suspect sensor. Disconnect PCM 104-pin connector. Check for damaged wiring, and repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between test pin No. 62 (EFT A) or 10 (EFT B) and test pins No. 24, 51 and 91. If any reading is less than 10,000 ohms, repair short circuit, and repeat QUICK TEST. If all readings are 10,000 ohms or more, replace PCM and repeat QUICK TEST .
  7. Step 7) Continuous Memory DTC P0182, P0183, P0187 Or P0188  These trouble codes indicate possible intermittent fault. Possible causes for these faults are:
    • Faulty sensor.
    • Faulty sensor connector.
    • Open or grounded circuit in harness.
    • Faulty PCM.

    With scan tester connected, turn ignition on. Access EFT A or EFT B PID. While observing PID, tap on sensor to simulate road shock. Wiggle sensor connector. If no change in temperature reading occurs, go to next step. If any change in temperature occurs, isolate fault and repair as necessary.

  8. Step 8) Check EEC-V Wiring Harness  While in PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated, isolate fault and repair as necessary. Clear memory, and repeat QUICK TEST . If no fault is found, go to next step.
  9. Step 9) Inspect PCM & Wiring Harness Connectors  Turn ignition off. Disconnect PCM 104-pin connector. Inspect connector for damaged pins, corrosion and loose wires. If connectors and terminals are damaged, repair as necessary and repeat QUICK TEST . If connectors and terminals are okay, fault cannot be duplicated at this time and testing is complete.
scientia non olet · About LEMON Manuals