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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 INDEX

Symptom Diagnostic procedure Also check for
Engine will not start (MIL works OK, no DTCs set)
  1. Test the battery (see BATTERY TEST ).
  2. Test the starter (see STARTER SOLENOID TEST ).
  3. Check the fuel pressure (see FUEL PRESSURE TEST ).
  • Low compression
  • No ignition spark
  • Intake vacuum leaks
  • Locked up engine
  • Broken timing belt
  • Fuel contamination
  • Restricted exhaust system
Engine will not start (MIL comes on and stays on, no DTCs set) Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
  • No power to PCM
  • No ground to PCM
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 SYMPTOM TROUBLESHOOTING ).  
Engine starts but stalls immediately (MIL works OK, no DTCs set, immobilizer indicator stays on or flashes) Check the immobilizer system (see SYMPTOM TROUBLESHOOTING ).
  • Low compression
  • Intake vacuum leaks
  • Fuel contamination
  • Weak spark
Engine is hard to start (MIL works OK, no DTCs set)
  1. Test the battery (see 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 PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  2. Check the idle speed (see IDLE SPEED INSPECTION ).
  3. Clean the throttle body (see THROTTLE POSITION LEARNING CHECK ).
  
Cold fast idle too high (MIL works OK, no DTCs set)
  1. Do the PCM idle learn procedure (see 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 leaks
Idle speed fluctuates (MIL works OK, no DTCs set)
  1. Do the PCM idle learn procedure (see 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 specification without load (MIL works OK, no DTCs set)
  1. Troubleshoot the alternator FR signal circuit (see ALTERNATOR FR SIGNAL CIRCUIT TROUBLESHOOTING ).
  2. Do the carbon accumulation check (see THROTTLE BODY TEST ).
 Incorrect valve timing
After warming up, idle speed is above specification without load (MIL works OK, no DTCs set)
  1. Troubleshoot the alternator FR signal circuit (see ALTERNATOR FR SIGNAL CIRCUIT TROUBLESHOOTING ).
  2. Inspect the APP sensor (see APP SENSOR SIGNAL INSPECTION ).
 Intake vacuum leaks
After warming up, idle speed drops when steering wheel is turned (MIL works OK, no DTCs set)
  1. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  2. Troubleshoot the PSP switch signal circuit (see PSP SWITCH SIGNAL CIRCUIT TROUBLESHOOTING ).
  3. Do the carbon accumulation check (see THROTTLE BODY TEST ).
 Power steering system problem
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
  • Intake restriction
Engine stalls (MIL works OK, no DTCs set)
  1. Do the PCM idle learn procedure (see 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
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 pipe and the fuel tank.
  3. Replace the fuel tank (see FUEL TANK REPLACEMENT ).
 Malfunctioning gas station filling nozzle.
Fuel overflows during refueling (No DTCs set) Replace the fuel tank (see FUEL TANK REPLACEMENT ). Malfunctioning gas station filling nozzle.
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 ).  
HDS does not communicate with the PCM or the vehicle Troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ). Correct HDS software
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