( TL19E30A20300000000HBAT00 )

Fuel and Emissions Systems 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)

1.
2.
3.
4.

Test the battery.
Test the starter.
Check the fuel pressure.
Troubleshoot the fuel pump circuit.

- Low compression
- No ignition spark
- Intake vacuum leaks
- Locked up engine
- Broken cam chain
- Fuel contamination

Engine will not start (MIL comes on and stays on, no DTCs set)

Troubleshoot the DLC circuit.

- Low compression
- No ignition spark
- Intake vacuum leaks
- Locked up engine
- Broken cam chain
- Fuel contamination
- No power ECM/PCM
- No ground ECM/PCM
- Shorted reference voltage

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.

- Camshaft timing
- Low compression
- Intake vacuum leaks
- Fuel contamination
- Weak spark

Engine is hard to start (MIL works OK, no DTCs set)

1.
2.
3.

Test the battery.
Check the fuel pressure.
Test the throttle body.

- Low compression
- Intake vacuum leaks
- Fuel contamination
- Weak spark

Cold fast idle too low (MIL works OK, no DTCs set) | 1. 2. 3. | Do the ECM/PCM idle learn procedure. Check the idle speed. Throttle body cleaning. | Incorrect valve adjustment
Cold fast idle too high (MIL works OK, no DTCs set) | 1. 2. 3. | Do the ECM/PCM idle learn procedure. Check the idle speed. Test the throttle body. | Incorrect valve adjustment

After warming up, idle speed is below specifications without load (MIL works OK, no DTCs set)

1.
2.

Troubleshoot the alternator FR signal circuit.
Test the throttle body.

- Intake vacuum leaks
- Incorrect Valve adjustment

After warming up, idle speed is above specifications without load (MIL works OK, no DTCs set) | 1. 2. | Troubleshoot the alternator FR signal circuit. Inspect the APP sensor. | Intake vacuum leaks

Idle speed fluctuates (MIL works OK, no DTCs set)

1.
2.
3.
4.
5.
6.
7.
8.

Do the ECM/PCM idle learn procedure.
Check the fuel pressure.
Except KN model: Test the injectors.
Troubleshoot the alternator FR signal circuit.
Inspect the PCV valve.
Test the throttle body.
Troubleshoot the A/C signal circuit.
Troubleshoot the VTEC system oil pressure.

- Fuel contamination
- Intake vacuum leaks

Misfire or rough running (MIL works OK, no DTCs set)

1.
2.
3.
4.
5.

Check the spark plugs.
Check the fuel pressure.
Test the injectors.
Troubleshoot the fuel pump circuit.
Troubleshoot the VTEC system oil pressure.

- Low compression
- Valve clearance
- Fuel contamination

Fails emission test (MIL works OK, no DTCs set)

1.
2.
3.
4.
5.
6.

Except KN model: Inspect the three way catalytic converter (TWC).
Except KN model: Check the spark plugs.
Check the fuel pressure.
Except KN model: Test the injectors.
Check the EVAP system.
Troubleshoot the VTEC system oil pressure.

- Fuel contamination
- Low compression
- Broken cam chain

Low power (MIL works OK, no DTCs set)

1.
2.
3.
4.
5.
6.

Check the fuel pressure.
Check the air cleaner element.
Test the throttle body.
Except KN model: Inspect the three way catalytic converter (TWC).
Except KN model: Test the injectors.
Troubleshoot the VTEC system oil pressure.

- Fuel contamination
- Low compression
- Camshaft timing
- Engine oil level

Engine stalls (MIL works OK, no DTCs set)

1.
2.
3.
4.
5.
6.

Do the ECM/PCM idle learn procedure.
Check the fuel pressure.
Check the idle speed.
Troubleshoot the brake pedal position switch signal circuit.
Except KN model: Check the spark plugs.
Troubleshoot the VTEC system oil pressure.

- Intake vacuum leaks
- Faulty harness and sensor connections
- Fuel contamination

Engine oil level indicator (amber) stays on or flashes, or CHECK SYSTEM (CHECK OIL LEVEL SENSOR) display is on (MIL works OK, no DTCs set) | Inspect the engine oil level sensor. |
HDS does not communicate with the ECM/PCM or the vehicle | Troubleshoot the DLC circuit. |
SIL never comes on | Troubleshoot shift indicator lamp. |
When the clutch pedal pressed, light out of SIL is slow | Troubleshoot shift indicator lamp. |
SIL does not work once in a while | Troubleshoot shift indicator lamp. |
Shift up indicator lamp does not come on, or shift down indicator lamp does not come on | Check for body electrical system DTCs. |
SIL stays on | Check for body electrical system DTCs. |