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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 TROUBLESHOOTING CHART

Symptom Diagnostic procedure Also check for
Engine will not start (MIL works OK, no DTCs set, IMA motor works OK)
  1. Test the 12 volt battery (see 12 VOLT BATTERY TEST ).
  2. Test the starter (see STARTER PERFORMANCE TEST ).
  3. Check the fuel pressure (see FUEL PRESSURE TEST ).
  4. Troubleshoot the fuel pump circuit (see FUEL PUMP CIRCUIT TROUBLESHOOTING ).
  • Low compression
  • No ignition spark
  • Restricted exhaust system
  • Intake vacuum leaks
  • Locked up engine
  • Broken cam chain
  • Fuel contamination
Engine will not start, and HDS does not communicate with the ECM/PCM (MIL comes on and stays on) Troubleshoot the ECM/PCM power and ground circuits (see ECM/PCM POWER AND GROUND CIRCUIT TROUBLESHOOTING ).
  • No power to ECM/PCM
  • No ground to ECM/PCM
  • Short in reference voltage circuit
MIL comes on and stays on, or never comes on at all, no DTCs set Troubleshoot the MIL circuit (see MIL CIRCUIT TROUBLESHOOTING ).  
Engine will not start (MIL works OK, no DTCs set, immobilizer indicator stays on or flashes) Check the immobilizer system (see SYSTEM CHECK ).  
Engine starts but stalls immediately (MIL works OK, no DTCs set, immobilizer indicator stays on or flashes) Check the immobilizer system (see SYSTEM CHECK ).
  • Low compression
  • Intake vacuum leak
  • Weak spark
  • Low fuel pressure
Engine is hard to start (MIL works OK, no DTCs set)
  1. Test the 12 volt battery (see 12 VOLT BATTERY TEST ).
  2. Check the fuel pressure (see FUEL PRESSURE TEST ).
  3. Clean the throttle body (see THROTTLE POSITION LEARNING CHECK ).
  • Low compression
  • Intake vacuum leaks
  • Fuel contamination
  • Weak spark
Cold fast idle too low (MIL works OK, no DTCs set)
  1. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  2. Check the idle speed (see IDLE SPEED INSPECTION ).
  3. Clean the throttle body (see THROTTLE POSITION LEARNING CHECK ).
  • Incorrect valve adjustment
  • Fuel contamination
Cold fast idle too high (MIL works OK, no DTCs set)
  1. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  2. Check the idle speed (see IDLE SPEED INSPECTION ).
  3. Do the throttle position learning check (see THROTTLE POSITION LEARNING CHECK ).
  • Intake vacuum leak
  • Incorrect valve adjustment
Idle speed fluctuates (MIL works OK, no DTCs set)
  1. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  2. Check the idle speed (see IDLE SPEED INSPECTION ).
  3. Do the carbon accumulation check (see THROTTLE BODY TEST ).
  4. Troubleshoot the A/C signal circuit (see A/C SIGNAL CIRCUIT TROUBLESHOOTING ).
  • Incorrect valve timing or clearance adjustment
  • Intake vacuum leaks
After warming up, idle speed is below specifications without load (MIL works OK, no DTCs set) Do the carbon accumulation check (see THROTTLE BODY TEST ).  
After warming up, idle speed is above specifications without load (MIL works OK, no DTCs set) Inspect the APP sensor (see APP SENSOR SIGNAL INSPECTION ).  
Low power (MIL works OK, no DTCs set) Check the fuel pressure (see FUEL PRESSURE TEST ).
  • Low compression
  • Incorrect camshaft timing
  • Incorrect engine oil level
  • Exhaust restriction
  • Fuel contamination
Engine stalls (MIL works OK, no DTCs set)
  1. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  2. Check the fuel pressure (see FUEL PRESSURE TEST ).
  3. Check the idle speed (see IDLE SPEED INSPECTION ).
  4. Troubleshoot the brake pedal position switch signal circuit (see BRAKE PEDAL POSITION SWITCH SIGNAL CIRCUIT TROUBLESHOOTING ).
  • Intake vacuum leaks
  • Faulty harness and sensor connections
  • Fuel contamination
Difficult to refuel (MIL works OK, no DTCs set)
  1. Check the fuel tank vapor control valve hose between the EVAP canister and the fuel tank.
  2. Inspect the fuel filler neck for restrictions.
  3. Replace the fuel tank unit (see FUEL TANK UNIT REMOVAL AND INSTALLATION ).
  4. Replace the fuel tank (see FUEL TANK REPLACEMENT ).
  • Malfunctioning gas station filling nozzle
  • Faulty fuel tank vapor control valve
Fuel cap warning message stays on (MIL works OK, no DTCs set) Troubleshoot the fuel cap warning message system (see DTC P145C: EVAP SYSTEM PURGE FLOW MALFUNCTION ). EVAP vacuum leak
SIL never comes on (M/T)
  1. Troubleshoot the shift indicator lamp (see SHIFT INDICATOR LAMP TROUBLESHOOTING ).
  2. Do the gauge control module self-diagnosis function (see SELF-DIAGNOSTIC FUNCTION ).
  
SIL stays on (M/T)
  1. Troubleshoot the shift indicator lamp (see SHIFT INDICATOR LAMP TROUBLESHOOTING ).
  2. Do the gauge control module self-diagnosis function (see SELF-DIAGNOSTIC FUNCTION ).
  
When the clutch pedal is pressed, the SIL is slow to go off (M/T) Troubleshoot the shift indicator lamp (see SHIFT INDICATOR LAMP TROUBLESHOOTING ).  
SIL does not work sometimes (M/T) Troubleshoot the shift indicator lamp (see SHIFT INDICATOR LAMP TROUBLESHOOTING ).  
HDS does not communicate with the ECM/PCM or the vehicle Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).  
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