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Home >> Jeep >> 1996 >> Cherokee Classic, Part Time, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 4.0L >> Diagnostic Trouble Code (DTC) Identification >> Test NTC-19A - Checking Fuel Heater

Test NTC-19A - Checking Fuel Heater

NOTE: For connector terminal identification, refer to CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article in this section.
NOTE: Test applies only if vehicle symptoms are: runs rich, hard to start, does not rev-up, or misses under load. If vehicle experiences these symptoms only when ambient temperature is 40°F (4.4°C) or more, this test does not apply.
  1. Disconnect fuel heater connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST VER-2A. If connector and terminals are okay, go to next step.
  2. Turn ignition on. Using scan tool in voltmeter mode, check voltage on fuel heater connector, fuel heater relay output circuit (Red/Black wire). If voltage is 10 volts or less, repair open fuel heater relay output circuit and perform TEST VER-2A . If voltage is more than 10 volts, go to next step.
  3. Turn ignition off. Using scan tool in ohmmeter mode, check resistance of fuel heater connector, ground circuit (Black/Tan wire). If resistance is 5 ohms or more, repair open ground circuit and perform TEST VER-2A. If resistance is less than 5 ohms, go to next step.
  4. Ensure fuel heater element temperature is less than 40°F (4.4°C). Using an external ohmmeter, check resistance across fuel heater connector terminals (component side). If resistance is not 2.4-3.1 ohms, replace fuel heater element and perform TEST VER-2A . If resistance is 2.4-3.1 ohms, fuel heater is operating normally. Test passed.