Fault Codes

Symptoms:

• The check engine light will be on
• The vehicles temperature may ruse enough to overheat the vehicle if the fan is not operating

Causes:

• Faulty cooling fan  1
• Poor electrical connection in the fan circuit
• Failed fan control relay has failed
• Failed coolant temperature sensor
• Faulty AC Pressure switch
• VSS not operating correctly

Possible Solutions:

• Replacing the VSS Sensor
• Replacing the engine coolant temp sensor
• Repairing or replacing of the fan wiring
• Replacing cooling fan 1
• Repairing electrical connection issues
• Replacing AC Pressure switch
• Replacing the fan control relay

Symptoms:

• Poor engine performance
• Insufficient turbocharger pressure
• The exhaust back pressure regulator may be automatically disabled if the PCM stores this code
• The check engine light will be on

Causes:

• Damaged or burnt out electrical wiring
• Damaged connectors
• Open circuits between the exhaust pressure sensor and the PCM
• Turbocharger over-boost
• In rare cases, a faulty PCM

Possible Solutions:

• Perform a visual inspection of all wiring and connectors, and repair any that appear damaged
• Clear the code from the PCM, and take the vehicle for a test drive to determine if the check engine light returns
• Remove and clean the exhaust back pressure tube and sensor
• Repair or replace other open or shorted wiring or connectors of all circuits
• Replace the solenoid

Symptoms:

• Insufficient turbocharger pressure
• Reduced engine performance
• Check engine light will come on

Causes:

• Damaged, corroded, loose or shorted electrical components, such as wiring or connectors
• Open or shorted exhaust back pressure valve
• Poor connection in the exhaust back pressure valve circuit
• Faulty PCM in some rare cases

Possible Solutions:

• Verify the code with an OBD-II Scanner or an exhaust back pressure step test
• Perform a visual inspection of the electrical components in the exhaust back system and repair any that are loose, corroded, faulty, open or shorted
• After each repair, perform a road test to ensure that the repair addressed the proper cause
• Replace or repair a faulty exhaust back pressure valve

Symptoms:

• Reduced engine performance
• Insufficient turbocharger pressure
• Check engine light

Causes:

• Faulty exhaust back pressure valve
• Opened or shorted exhaust back pressure valve
• Poor electrical connection in the exhaust back pressure valve circuit
• Faults in the exhaust back pressure
• Engine oil temperature
• Intake air temperature sensors

Possible Solutions:

• Unclogging or repairing the back pressure tube
• Cleaning, repairing or replacing the exhaust back pressure sensor
• Repairing or replacing a faulty exhaust back pressure valve
• Repairing or replacing an opened or shorted exhaust back pressure valve
• Repairing a poor electrical connection in the exhaust back pressure valve circuit

Symptoms:

• Check engine light will come on

Causes:

• Faulty exhaust back pressure valve
• Open or shorted Exhaust back pressure valve
• Poor electrical connection in the Exhaust back pressure valve

Possible Solutions:

• Run through a diagnostic test before you begin any repairs
• Start small, if that does not provide solution, you can start replacing larger components on your vehicle

Symptoms:

• The check engine light

Causes:

• A faulty exhaust back pressure valve
• The exhaust back pressure valve is shorted out or open
• Poor electrical connection on your exhaust back pressure valve

Possible Solutions:

• Faulty connections
• Test the solenoid and its circuits
• If the solenoid is either shorted or open, you will need to replace the solenoid
• Repair any faulty wiring

Symptoms:

• The exhaust back pressure regulator will be disabled, in either a closed or open position
• Reduced engine performance and insufficient turbocharger pressure
• The check engine warning light with be illuminated

Causes:

• Damaged electrical wiring and connectors
• Shorted or open exhaust back pressure sensor harness
• Faulty PCM, in very rare cases

Possible Solutions:

• Clearing or replacing a clogged back pressure tube
• Replacing or cleaning a faulty exhaust back pressure sensor
• Replacing or repairing a shorted or open exhaust back pressure sensor
• Manually test individual circuits within the exhaust back pressure system, and replace any faulty components
• In rare cases, replacing a faulty PCM

Symptoms:

• Reduced fuel economy
• Engine hesitation
• Reduced engine performance
• Hissing sound on acceleration

Causes:

• Failed oxygen sensor
• An air leak in the exhaust before the catalytic converter

Possible Solutions:

• Replacing a failed catalytic converter
• Replacing a failed oxygen sensor
• Repairing exhaust leaks ahead of the converter
• Repairing or replacing damaged wiring or corroded connections

Symptoms:

• The check engine light will be illuminated
• The engine may not have any drive symptoms
• Catalyst damage and/ or clogging of the exhaust
• Loss of power and misfiring

Causes:

• The bank 1 catalyst has lost its efficiency or has broken apart inside and needs to be replaced
• The air injection system is not pumping the correct amount of air or too much air into the bank 1 catalyst due to a fault in the air injection system
• The 02 Sensor post catalyst on bank 1 is not working to specifications

Possible Solutions:

• Replacing the post O2 Sensor for bank 1
• Replacing the catalyst on bank 1
• Repairing the wiring to the O2 sensors if they got burnt on the exhaust

Symptoms:

• In some cases, no symptoms
• Check engine light is on
• Loss of power
• Engine stalling
• Engine hesitating on acceleration
• Hissing noise on acceleration
• No start

Causes:

• A failed catalytic converter (multiple reasons for failure, including excess fuel being dumped into the exhaust, premature failure, internal component melting and more)
• A failed oxygen sensor
• A leak in the exhaust system above the catalytic converter

Possible Solutions:

• Replacing a failed catalytic converter
• Replacing a failed oxygen sensor
• Repairing exhaust leaks ahead of the catalytic converter

Symptoms:

• No noticeable issues whilst driving the vehicle.

Causes:

• Improperly functioning catalytic converter
• Too much or too little fuel
• Contamination from engine oil
• Faulty components
• Leaks
• Oxygen sensor malfunction

Possible Solutions:

• Broken or faulty parts related to the catalytic converter should be fixed or replaced as needed
• Replace the catalytic converter
• Give the vehicle a retest following each individual repair in order to pinpoint the cause of the issue

Symptoms:

• The presence of the check engine light displaying on the dashboard
• The vehicle may have a dipping idle and a slight lack of power
• Catalytic codes may make the check engine light flash

Causes:

• Faulty Catalytic converter
• Engine Misfire
• Fuel injector leaking
• Engine mechanical damage
• Oxygen sensor that has improper readings
• Exhaust leaks

Possible Solutions:

• Replacing the catalytic converter
• Diagnosing and repairing the engine misfire
• Replacing the fuel injector
• Repairing any mechanical damages in the engine
• Replacing the oxygen sensor
• Repairing or replacing the exhaust

Symptoms:

• Illumination of the check engine light

Causes:

• A defective catalytic converter
• A faulty oxygen sensor
• An air leak before the catalytic converter

Possible Solutions:

• Replacing the oxygen sensor
• Repairing an air leak before the catalytic converter
• Replacing the PCM (rare)

Symptoms:

• Check engine light will be illuminated
• The engine may not have any drive symptoms except a check engine light
• Catalyst is damaged and clogging the exhaust
• Loss of power/ misfiring

Causes:

• The bank 1 catalyst has lost its efficiency or has broken apart inside and needs replacing
• The air injection system is not pumping the correct amount of air or too much air into the bank 1 catalyst due to a fault in the air injection system
• The O2 sensor post catalyst on bank 1 is not working to specifications

Possible Solutions:

• Replacing the post O2 sensor for bank 1
• Replacing the catalyst on bank 1
• Repairing the wiring to the O2 sensors if they got burnt on the exhaust

Symptoms:

• Check the engine soon warning light
• Diminished engine performance
• Hissing noises
• Hesitation when the throttle is engaged
• Engine stalling/ will not start

Causes:

• Faulty oxygen sensor
• Malfunctioning coolant temperature sensor
• Faulty fuel pressure regulator
• Faulty manifold air pressure sensor
• Malfunctioning mass air flow sensor
• Contaminated engine oil
• Engine leaks upstream from the catalytic converter
• Engine is misfiring
• Loose or damaged wires and connectors

Possible Solutions:

• Replacement of oxygen sensors
• New wiring or electrical connectors
• Fix engine leaks
• Replacement of the mass air flow sensor
• Replacement of the manifold air pressure sensor
• Replacement of the fuel pressure regulator
• Replacement of the coolant temperature sensor
• Replacement of the Catalytic Converter

Symptoms:

• The Check Engine Light will be illuminated
• The may not start
• The engine may lack power or hesitate upon acceleration
• Strange noises may be heard whilst driving

Causes:

• A faulty catalytic converter
• A faulty oxygen sensor
• Damaged oxygen sensor circuitry
• A faulty powertrain control module

Possible Solutions:

• Repairing or replacing wiring that is associated with the oxygen sensor
• Replacing the oxygen sensor
• Replacing the powertrain control module
• Replacing the catalytic converter

Symptoms:

1. Back pressure regulator could be malfunctioning
2. Engine isn't performing as well as it should be
3. Lack of turbocharge pressure which could trigger the code
4. Check engine light
5. Check other associated codes

Causes:

1. Back pressure tube of your vehicle is clogged
2. The back pressure sensor could also be suffering from clog
3. Damaged electrical wiring and connectors could also be the reason and, typically, they've been burnt and therefore aren't working
4. The PCM could simply be at fault, but this is the least likely reason

Possible Solutions:

1. Checking and repairing any exhaust leaks
2. Checking for and repairing any wiring or connector problems (They may just need a thorough cleaning too)
3. After repairs that appear to clear the code, the vehicle should be test driven to see if it returns

Symptoms:

1. Lack of power to the engine
2. Seeing the check engine light come on
3. A manual regeneration is unable to perform
4. A crank-no start (if a regeneration isn't able to perform)

Causes:

1. The exhaust back pressure sensor is no longer working correctly
2. Exhaust back pressure sensor is suffering from a poor electrical connection
3. The exhaust back pressure sensor harness is shorted or open
4. There is an open in signal circuit occurring between the PCM and exhaust pressure sensor
5. Short of power to ground in the signal circuit to the exhaust pressure sensor

Possible Solution:

1. Replacing any damaged wires in the EPS and/ or cleaning them
2. If the connectors were the problem, then erasing the code from the memory should result in a clear screen as opposed to the code returning
3. If the code returns, testing the sensor and its circuits
4. Checking the voltage of the EPS to see if it has suffered from failure

Symptoms:

1. If the code becomes stored, it could disable the exhaust back pressure regulator
2. Diminished engine performance
3. The engine light will also light up
4. Other codes related to the exhaust system or the turbocharger could also be stored

Causes:

1. Exhaust gas pressure sensor
2. Something could be blocking the tube that runs from the exhaust manifold to the pressure sensor
3. Issues with the exhaust gas recirculation system
4. Potential issue with the powertrain control module, although this is a quite rare

Possible Solutions:

1. Use an OBD-II Scanner to diagnose the vehicle and see if the code returns
2. Check wiring and connectors to make sure nothing is shorted or corroded
3. Check the exhaust pressure sensor
4. Check the tubing that connects the exhaust pressure to the exhaust manifold

Symptoms:

You likely won't notice any

Causes:

1. Loose or improperly affixed gas cap
2. Other leak or damaged piece in EVAP system

Possible Solutions:

1. Remove and reinstall the gas cap
2. Clear the code and drive for a day and see if the code come back
3. Replace the gas cap
4. Inspect/ replace the EVAP system for cuts/ holes in tubes/ hoses

P0455 indicates a fuel vapor leak or lack of purge flow in the EVAP control system. It means a large leak has been detected. The EVAP emission control system prevents the escape of fuel vapours from a vehicles fuel system. Fuel vapours are routed by hoses to a charcoal canister for storage. When the engine is running, a purge control valve opens allowing intake vacuum to siphon the fuel capers into the engine.

Symptoms:

1. Harder to start
2. Engine may stumble or hesitate or not start at all
3. Eggy smell

Causes:

1. Faulty spark plugs or wires
2. Faulty coil pack
3. Faulty oxygen sensor(s)
4. Faulty fuel injector
5. Burned exhaust valve
6. Faulty catalyst
7. Stuck/blocked/leaking EGR Valve/ Passages
8. Faulty camshaft position sensor
9. Low fuel

Possible solutions:

1. Reset the code and see if it comes back
2. Check all wiring and connectors that lead to the cylinders
3. Replace ignition components (spark plugs, spark plug wires, coil pack)
4. Check the fuel injectors
5. Smell egg? Replace the Catalytic Converter

P0300 Diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring.

Symptoms:

1. This code should be considered as severe
2. Excessive black smoke
3. Inability to produce and maintain desired RPM levels
4. Increased engine temperature
5. Overheated DPR housing or other exhaust components

Possible Causes:

1. Excessive soot accumulation due to insufficient DPG Regeneration
2. DPF Pressure Sensor
3. Insufficient diesel exhaust fluid
4. Incorrect diesel exhaust fluid
5. Wiring to the DPF injection system
6. Exhaust pressure Sensor(s)

Possible Solutions:

1. Check technical service bulletins
2. It may be a known fault with the vehicle manufacturer (could save time and money)
3. Diagnostic Scanner

Symptoms:

1. Engine light usually comes on it this code is present
2. Lack of power from your engine
3. Manual regeneration will be impossible
4. Eventually the problem may evolve into a crank-no start

Causes:

1. Damaged, burnt, shorted, disconnected or corroded wiring and/ or connectors in the back pressure sensors' reference and/ or signal circuits
2. Defective exhaust back pressure sensor
3. Clogged or restricted exhaust gas feeding tube
4. Boost pressure leaks on applications where the sensor is used for boost pressure
5. Blockages or restrictions in the exhaust system
6. Failed or failing PCM

Possible Solutions:

1. Replace the back pressure sensor
2. Test associated circuits to make sure they former isn't malfunctioning
3. Check the power supply for the sensor will also be tested to confirm it is not the reason that its not working
4. The power supply to the exhaust pressure sensor should be gauged

Symptoms:

The main symptom to the driver is the illumination of the MIL (Malfunction Indicator Lamp). You will likely not notice any drivability problems. If the substrate inside the catalytic converter is broken or failed, it may be restricting the exhaust which will result in a feeling of reduced power or poor engine running.

Possible Causes:

1. Leaking Exhaust Manifold; CAT; Silencer or Exhaust Pipe
2. Damaged or failed 02 Sensor
3. Engine coolant temperature sensor
4. Ignition issues
5. Poorly performing catalyst
6. Impact damage
7. Coolant contamination

Possible Solutions:

1. Replace faulty exhaust components
2. Test or replace 02 Sensor
3. Remedy faulty ignition
4. Replace the catalyst if necessary

Causes:

1. DPF (Diesel Particulate Filter) is full of ash
2. Damaged DPF Pressure sensor
3. Faulty exhaust gas temperature (EGT)
4. EGT harness open or shorted
5. EGT circuit poor electrical connection
6. Faulty mass air flow (MAF)/ intake air temperature (IAT) sensor

Symptoms:

1. Loss of power in your engine
2. The DPF light will appear on your dashboard
3. Passive and active regeneration keep failing
4. A pungent smell of diesel
5. Your car seems to be releasing an excessive amount of smoke

Possible Solutions:

1. DPF Replacement
2. Check for faulty sensors, circuit and wiring issue and resolve immediately
3. Clean the DPF properly
4. PCM might need reprogramming

Causes:

1. Faulty DPF (Diesel Particulate Filter)
2. Exhaust leaks before or near the DPF Pressure Sensor
3. Leaks in the DPF pressure sensor hose
4. Aftermarket accessories and performance modifications
5. Improper DPF Regeneration Fluid
6. Clogged up DPF pressure sensor tubes/hoses

Symptoms:

1. Diminished engine performance
2. Decreased fuel efficiency
3. Excessive black smoke from the exhaust
4. Increased engine temperatures
5. Increased automatic transmission temperatures

Possible Solutions:

1. Replacing a shorted DPF and run a regeneration to clean the particulate filter
2. Repairing the connections to the DPF
3. Purchase the correct regeneration fluid
4. Remove any aftermarket modifications

Possible Causes:

1. Vacuum Leaks
2. Clogged or faulty MAF (Mass Air Flow) Sensor
3. Faulty EGR Valve or other parts of EGR System
4. Faulty Oxygen Sensor
5. Inlet Manifold leaks
6. Improperly installed aftermarket intake
7. Low fuel pressure
8. Clogged up Catalytic Converter

Possible Solutions:

1. Inspect all vacuum pipes and EGR System
2. Replace MAF if necessary
3. Inspect/ or test the intake manifold gaskets for leakage
4. Check for a dirty fuel filter
5. Check for a dirty fuel filter
6. Check for proper fuel pressure
7. Replace the catalyst is necessary