Fuel and Emissions Systems Symptom Troubleshooting Index
Symptom Troubleshooting Index

When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the HDS. If there is no DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.

Symptom
Diagnostic procedure
Also check for
Engine will not start
(MIL works OK, no DTCs set)
Troubleshoot the engine will not start, engine start but stalls immediately, or engine is hard to start.
  
Engine will not start and HDS does not communicate with the PCM
(MIL comes on and stays on, no DTCs set)
PCM power and ground circuit troubleshooting.
  
MIL comes on and stays on, or never comes on at all, no DTCs set
Troubleshoot the MIL circuit.
  
Engine will not start
(MIL works OK, no DTCs set, immobilizer indicator stays on or flashes)
Check the immobilizer system.
  
Engine starts but stalls immediately
(MIL works OK, no DTCs set, immobilizer indicator stays on or flashes)
Check the immobilizer system.
  
Engine is hard to start
(MIL works OK, no DTCs set)
Troubleshoot the engine will not start, engine start but stalls immediately, or engine is hard to start.
  
Cold fast idle too low
(MIL works OK, no DTCs set)
  
Cold fast idle too high
(MIL works OK, no DTCs set)
Intake air leaks
Idle speed fluctuates
(MIL works OK, no DTCs set)
Incorrect valve adjustment
Intake air leaks
After warming up, idle speed is below specifications without load
(MIL works OK, no DTCs set)
Do the carbon accumulation check.
Incorrect valve timing or clearance adjustment
After warming up, idle speed is above specifications without load
(MIL works OK, no DTCs set)
Inspect the APP sensor.
Intake air leaks
Low power
(MIL works OK, no DTCs set)
Low compression
Incorrect camshaft timing
Incorrect engine oil level
Exhaust restriction
Fuel contamination
Engine stalls
(MIL works OK, no DTCs set)
Troubleshoot the engine stalls.
  
Difficult to refuel
(MIL works OK, NO DTCs set)
1.
Check the fuel vent tube between the EVAP canister and the fuel tank.
2.
Check the fuel tank vapor recirculation tube between the fuel fill pipe and the fuel tank.
3.
Replace the fuel tank.
Malfunctioning gas station filling nozzle
Fuel overflows during refueling
(No DTCs set)
Replace the fuel tank.
Malfunctioning gas station filling nozzle
Fuel cap warning message stays on
(MIL works OK, no DTCs set)
Do the troubleshooting procedure for DTC P0455 and P0456, if the fuel cap warning message comes on frequently, or if the message does not go off after the fuel fill cap is tightened and the vehicle is driven several days..

NOTE: Fuel cap warning message is monitored during the engine off natural vacuum (EONV) testing.
  
HDS does not communicate with the PCM or the vehicle
Troubleshoot the DLC circuit.
Correct HDS software