STEP/SEQUENCE RESULT WHAT TO DO NEXT TM 9-2320-363-20-1 Section 4 TROUBLESHOOTING CHARTS E.  FLASH CODE: 24 J1587 CODE: P174 4 - FUEL TEMPERATURE CIRCUIT FAILED LOW (LOW VOLTAGE) NOTE -  This chart is only to be used if: 1) All basic mechanical checks and physical inspections have been performed with no problem found, and 2) Diagnosis of DDEC-III was started at step Start-1, pg 3-345.41 and you have now been referred here. 24-1 Multiple Code Check Were there any other active No other codes. Go to 24-2. codes besides Code 174/4? Yes, any or all, Go to ENG5V-1 (page 3-345.413). of the following codes: 110/3, 17513, 174/3, 102/3. Yes - but none Go to 24-2. of the above. 24-2 Sensor Check Turn ignition off. Code 174/3 ( or any Go to 24-3. Disconnect FTS connector. other codes except Start engine and run until "Check Code 174/4). Engine" light comes on or for 8 minutes. Code 174/4 (and any Go to 24-4. Read active codes with engine other codes). still running. 24-3 Check FTS Connectors Inspect terminals at the FTS Terminals and Replace FTS.  Then go to connectors (both the sensor and connectors are okay. 24-30. harness side) for damage; bent, corroded, and unseated pins or Problem found A Repair terminals/connectors. sockets. Then go to 24-30. 23-4 Open line Check Turn ignition off. Less than or Signal line (ckt#472) is shorted equal to 10,000 ohms Disconnect the engine harness on either reading. to the return line (ckt#452) or connector at the ECM. battery ground.  Repair short. Read resistance between sockets Then go to 24-30. R3 and Y2 on the engine harness connector. Greater than Go to 24-5. Also read resistance between 10,000 ohms or open socket B and a good ground. on both readings Change 3  3-345.249