STEP/SEQUENCE RESULT WHAT TO DO NEXT TM 9-2320-363-20-1 Section 4 TROUBLESHOOTING CHARTS E. FLASH CODE: 23 J1587 CODE: P174 3. FUEL TEMPERATURE CIRCUIT FAILED HIGH (HIGH 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 23-1 Sensor Check Turn ignition off. Code 174/4 and/or Go to 23-2. Disconnect FTS and install a any codes except jumper wire between the FTS Code 174/3). connector sockets A and B. Turn ignition on. Anything except Go to 23-4. Read Active codes. Code 174/4. 23-2 Check for Short to +5 Volt Line Turn ignition off. Less than or Signal line (ckt#472) is shorted Remove jumper wire. equal to 10,000 ohms. to the engine +5 Volt line (ckt Disconnect the engine harness #416), and/or (ckt#472) signal connector at the ECM. is shorted to (ckt#452) sensor Read resistance between sockets return and/or ground. Repair R3 and W1 on the engine harness short. Then go to 23-30. connector. Greater than Go to 23-3. 10,000 ohms or open. 23.3 Check FTS Connectors Inspect terminals at the FTS Terminals and Replace FTS. Then go to connectors (both the sensor and connectors are okay. 23-30. harness side) for damage; bent, corroded, and unseated pins or Problem found. Repair terminals/connectors. sockets. Then go to 23-30. 23.4 Open Line Check Turn ignition off. Less than or Go to 23-5. Disconnect the engine harness equal to 5 ohms connector at the ECM. Read resistance between sockets Greater than Signal line (ckt#472) or return R3 and Y2 on the engine harness 5 ohms or open. line (ckt#452) is open. Repair connector. open Then go to 23-30. Change 3  3-345.245