P067F Cylinder 6 Glow Plug Circuit High

P067F Cylinder 6 Glow Plug Circuit High

OBD-II DTC Datasheet

High signal level in a chain of a glow plug of cylinder 6

What does this mean?

This Generic Powertrain Diagnostic Trouble Code (DTC) is commonly applied to many OBD-II vehicles. This may include, but is not limited to, Jeep, Chrysler, BMW, Toyota, Volkswagen, Dodge, Ram, Ford, Chevrolet, Mazda, etc.

When a code P067F is set, it means that the powertrain control module (PCM) has detected a high voltage situation in the glow plug control circuit for cylinder # 6. Consult a reliable vehicle service resource for the location of the indicated cylinder in the code description for your specific year. engine make, model and configuration.

Diesel engines use strong compression instead of a spark to start the piston movement. Since there is no spark, the cylinder temperature must be increased for maximum compression. For this, glow plugs are used in each cylinder.

The individual cylinder glow plug, which is often confused with spark plugs, is screwed into the cylinder head. Battery voltage is supplied to the glow plug element through the glow plug timer (sometimes called the glow plug controller or glow plug module) and / or the PCM. When voltage is applied correctly to the glow plug, it literally glows red hot and raises the temperature of the cylinder. As soon as the cylinder temperature reaches the desired level, the control unit limits the voltage and the glow plug returns to normal.

If the PCM detects that the voltage level for the cylinder 6 glow plug control circuit is higher than expected, a P067F code will be stored and a malfunction indicator lamp (MIL) may illuminate.

An example of a photo of a glow plug:

What is the severity of this DTC?

Any code related to glow plugs is likely to come with driveability issues. The stored code P067F should be urgently referred to.

What are some of the symptoms of the code?

Symptoms of a P067F trouble code may include:

• Excessive black smoke from exhaust gases
• Engine control problems
• Delayed engine start
• Reduced fuel efficiency
• Engine misfire codes can be saved

What are some of the common causes for the code?

Reasons for this code may include:

• Bad glow plug
• Open or short circuit in the glow plug control circuit
• Loose or defective glow plug connector
• Glow plug timer defective

What are some steps to troubleshoot the P067F?

An accurate diagnosis of the P067F code will require a diagnostic scanner, a reliable source of vehicle information, and a digital volt / ohmmeter (DVOM). Use your vehicle information source to find the appropriate Technical Service Bulletins (TSB). Finding a TSB that matches the make and model of the vehicle, the symptoms shown and the stored code will help you diagnose.

You may also need to obtain diagnostic block diagrams, wiring diagrams, connector views, connector pinout diagrams, component locations, and component test procedures / specifications from your vehicle information source. All this information will be needed to correctly diagnose a stored P067F code.

After thoroughly visually inspecting all glow plug wiring and connectors and glow plug control, connect the diagnostic scanner to the vehicle diagnostic port. Now extract all stored codes and freeze frame data and write them down for later use (just in case you need them). Then I would test drive the car to see if the P067F code has been reset. Move until one of two things happens: either the PCM enters ready mode or the code is cleared. If the code is cleared, continue diagnostics. If not, you are dealing with a recurrent illness that may need to get worse before an accurate diagnosis can be made.

Here's a tip that the service manual won't give you. A reliable way to test the glow plugs is to remove them and apply battery voltage. If the glow plug glows bright red, that's good. If the glow doesn't heat up and you want to take the time to test it with a DVOM, you'll probably find it doesn't meet the manufacturer's specifications for resistance. When performing this test, be careful not to burn yourself or cause a fire.

If the glow plugs are working properly, use the scanner to activate the glow plug timer and check the battery voltage (and ground) at the glow plug connector (use a DVOM). If no voltage is present, check the power supply for the glow plug timer or glow plug controller. Check all relevant fuses and relays according to the manufacturer's recommendations. In general, I find it best to test system fuses and fuses with a loaded circuit. A fuse for a circuit that is not loaded can be good (when it is not) and lead you to the wrong path of diagnosis.

If all fuses and relays work, use the DVOM to test the output voltage at the glow plug timer or PCM (wherever). If voltage is detected on the glow plug timer or PCM, suspect you have an open or short circuit. You can find the reason for the mismatch or simply replace the chain.

• It is sometimes thought that the P067F cannot be caused by a faulty glow plug because it is a control circuit code. Don't be fooled; A bad glow plug can cause a change in the control circuit, resulting in just such a code.
• Attempts to diagnose the wrong cylinder happen more often than you think. Save yourself a severe headache and make sure you are referring to the correct cylinder before starting your diagnosis.

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