P0681 OBD Error Code: Problem & Solutions

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Engine hard starts, stalling with reduced acceleration and affected fuel economy are direct systems of some problem with the vehicle’s engine. If OBD code P0681 is stored in the PCM, it means there is some problem with the glow plug circuit in the cylinder 11 of the engine.

OBD-II Code Hard or no start in cold weather is defined as a Cylinder 11 Glow Plug Circuit/Open.

OBD code P0681 applies to diesel vehicles and it means that the glow plug in cylinder 11 has failed to produce the high level of heat required to perform a cold start in a diesel engine. All diesels devices to heat the cylinders enough to ignite the fuel when the engine is cold, and this code identifies the Cylinder 11 glow plug circuit as the problem.

The glow plug control module applies power to the glow plugs. The module is generally incorporated in the engine management computer, although so vehicles will have it separately. Too long an activation will melt the glow plugs as they produce heat through heavy resistance and glow red hot while activated. This intense heat is quickly transferred to the cylinder head which allows the heat of combustion to maintain its heat for the fraction of a second it takes to ignite the incoming fuel for starting.

What causes this problem with the Cylinder 11 Glow Plug Circuit?

• Fault in the cylinder 11 glow plug
• Damages in the wiring connector
• An open or shorted circuit in the glow plug
• Control module for the glow plugs is faulty

1. Glow Plug - Check for faults in the Cylinder 11 Glow Plug and replace if needed. Buy new glow plug now!
2. Glow Plug Connector - Faulty or damaged wiring connector to the cylinder 11 glow plug should be replace, if necessary. Buy new connector now!
3. Glow Plug Relay - Check for faulty glow plug relay in association to the cylinder 11 and replace it now! Buy new glow plug relay from us!
4. Starter Relay - Check for the starter relay problems that can also be faulty and should be replaced at first instance. Buy new starter relay now!
5. Engine Control Module - Faulty ECM leads to engine stalling or not starting, and check engine lights being on. Replace damaged ECM now!
6. Powertrain Control Module - PCM related issues can hamper the fuel delivery system and engine performance. Find all the Powertrain related parts with us.
7. Diagnostic Tool - You will need high grade diagnostic tools for correction of the OBD error code which is detected. Visit us today to grab amazing deals.
8. Engine Wiring Connector - Engine wiring and connector at fault must be replaced if found faulty. Buy new engine wiring and connectors now!

It is vital to know the symptoms of an issue as only then you would be able to solve the problem. So that’s why we have listed out some major symptoms of OBD Code P0681 here:

Common Symptoms

• Engine Hard starting or no start condition
• Lacks of power until it heats up completely
• Hesitation when accelerating
• Engine miss due to cylinder head temperature being colder than normal
• No preheat period, preheat light doesn’t go off

Want to correct the Trouble Code P0681? Read these points mentioned below:

• Repair or replace any damaged, corroded, or loose wiring, connectors, and harnesses
• Replacing blown fuses and repair shorts
• Repair or replace damaged or bent pins in electrical connectors
• Replacing the cylinder 11 glow plug
• Replacing the glow plug relay

Apart from this, you might need to replace other damaged parts too like Power Control Module, Engine Control Module, Glow Plug, Glow Plug Relay, Glow Plug Control Module Glow plug wiring harness, Glow Plug Connector, Connector Engine connections and more. You can easily find all these parts with us. Not only that you can get these parts shipped to your door free, if your cart value happens to exceed $99.

It is essential to diagnose this fault code. Here are some steps which a mechanic should follow for diagnosing the problem that triggered a P0681 code to be stored:

• To diagnose this code, start by using a DVOM (digital volt-ohmmeter). Disconnect the glow plug connector, set the DVOM on ohms and place the red lead on the terminal of the glow plug and at the back end of a good ground.
• The range should be between 0.5 to 2.0 ohms. Verify the measurements from the factory service manual. If the range is outside the specifications, then the glow plug must be replaced.
• Next, check the resistance in glow plug wire to the glow plug relay buss bar on the valve cover. Notice how the relay (which looks like a starter relay) has large gauge wire that leads to a buss bar where all the wires of the glow plugs are attached.
• Next, test the wire to the cylinder 11 glow plug by replacing the red lead on the bus bar wire and the black lead to the glow plug inside. Once again, the range must be 0.5 to 2.0 ohms (with 2 ohms being the highest resistance).
• If the resistance is higher, then the wires from the buss bar to the glow plug must be replaced. Make sure to reconnect wires, as this may cause the buss bar to splurge.
• Then, technicians look for signs of cracks, looseness, or missing insulation. Lastly, connect the code scanner to the OBD port on the vehicle (usually located under the dash), turn the key at “on” with the engine off. Then clear the codes and test if the vehicle to see if the error code returns again.

Common Mistakes When Diagnosing the P0681 Code

Oftentimes the PCM sensor and circuit is blamed, and replaced, without checking the circuit as well as neglecting the damaged wiring and connectors. Because there can be several causes for this code, a complete inspection should be carried out in order to avoid repairs that may be unnecessary and more expensive.