DB: Engine Fuel Temperature (EFT) Sensor

DB: Introduction See: DB: Engine Fuel Temperature (EFT) Sensor - Introduction

DB1 DTC P0181 CHECK FOR KOER DTCS

• Start engine and bring up to operating temperature.
• Check for KOER DTCs.

Is DTC P0182 or P0183 present during KOER?
Yes

• For DTC P0181 with DTC P0182 or P0183. GO to DB2

.

No

• For DTC P0181 only. COMPLETE an OBD-II Drive Cycle (REFER to Section 2, Drive Cycles See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Drive Cycles). GO to DB2

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DB2 DTC P0180, P0181, P0182 and P0183: VERIFY ELECTRICAL FAULT CONDITION BY SIMULATING OPPOSITE SIGNAL TO PCM

• Disconnect engine fuel temperature sensor.
• Access EFTA-V PID value.
• Install jumper across terminals at the vehicle harness connector.

Note: If a scan tool communication concern exists, remove jumper wire immediately and GO to DB5.

• Record new reading.

Is the original reading of the EFTA-V PID with the harness disconnected greater than 4.5 volts or (-40°C/-40°F) and less than 0.21 volt or (135°C/275 °F) with the jumper installed?
Yes

• KEY OFF. REPLACE EFTA sensor. REFER to Computers and Control Systems.

No

• KEY OFF. FOR EFTA-V reading less than 4.54 volts with harness disconnected and jumper removed: GO to DB3

.

• FOR DTC P0182: GO to DB3

.

• FOR EFTA-V reading greater than 0.2 volt with harness disconnected and jumper installed: GO to DB5

.

• FOR DTC P0183: GO to DB5

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DB3 CHECK VREF CIRCUIT VOLTAGE AT FRP SENSOR

Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

• Disconnect fuel rail pressure (FRP)sensor.
• Key on, engine off.
• Measure voltage between VREF and SIG RTN at the fuel rail pressure (FRP) sensor harness connector.

Is voltage between 4.0 and 6.0 volts?
Yes

• GO to DB4

.

No

• GO to C1 See: C: Reference Voltage - Pinpoint Test

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DB4 CHECK EFT CIRCUIT FOR SHORT TO SIG RTN IN HARNESS

• Disconnect PCM.
• Measure resistance between EFT and SIG RTN circuits at the PCM harness connector.

Is each resistance greater than 10,000 ohms?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPAIR short circuit.

DB5 CHECK EFT SIGNAL FOR SHORT TO VREF

• Temperature sensor disconnected.
• PCM disconnected.
• Measure resistance between EFT and VREF circuits at the PCM harness connector.

Is each resistance greater than 10,000 ohms?
Yes

• GO to DB6

.

No

• LOCATE and REPAIR short to VREF.

DB6 CHECK EFT SIGNAL AND SIG RTN CIRCUITS FOR OPEN IN HARNESS

• Measure resistance of EFT circuit between PCM harness connector pin and EFT sensor harness connector.
• Measure resistance of SIG RTN circuit between PCM harness connector pin and EFT sensor harness connector.

Is each resistance less than 5.0 ohms?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• REPAIR open circuits.

DB7 DTCS P0180, P0181, P0182 and P0183: INTERMITTENT CHECK

• Key on.
• Access EFT-A PID.
• While monitoring EFT-A PID, perform the following: Tap on the sensor to simulate road shock. Wiggle the sensor connector.

Was there any change in the temperature reading?
Yes

• DISCONNECT and INSPECT connectors. If OK, REPLACE the sensor.

No

• GO to DB8

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DB8 WIGGLE TEST OF SENSOR WIRING HARNESS

• While monitoring EFT-A PID, hold the vehicle harness close to the sensor connector. Wiggle, shake and bend small sections of wiring harness while working toward the PCM.

Was there any change in the temperature reading?
Yes

• REPAIR as necessary.

No

• Fault is not present at this time.