Causes of obd2 code P067A
From years in the shop, I can tell you the causes of a P067A code are usually pretty clear-cut. Here’s what I run into most often:
- A worn-out glow plug in cylinder 4-these little guys don’t last forever.
- Damaged or brittle wiring in the glow plug circuit-wires near the engine take a real beating from heat and vibration.
- Loose or corroded connectors at the glow plug-sometimes, it’s just a poor connection making all the trouble.
- A faulty glow plug timer or control module-the component that decides when and how long power goes to the plugs.
More often than not, the glow plug itself is the problem, but don’t overlook wiring or the control module. I’ve seen those cause their fair share of headaches, too.
Symptoms of dtc P067A
When you run into this code, there are a few telltale signs I’ve seen over and over again. Usually, you’ll notice:
- Tough starts, especially when the weather turns cold.
- Rough idle or chugging right after startup.
- More black smoke than usual from the exhaust-that’s unburned fuel, thanks to a cold cylinder.
- Your fuel mileage might take a hit.
- Occasionally, you’ll feel a misfire or a sluggish engine for the first few minutes.
If any of this sounds familiar, don’t wait around-these issues can snowball fast if left alone.
Diagnosis steps for obd code P067A
When I’m tracking down a P067A, here’s my tried-and-true approach:
- Start with a good old-fashioned visual inspection. Pop the hood and look closely at the wiring and connectors for cylinder 4’s glow plug. I’m hunting for cracked insulation, loose plugs, or any sign of corrosion.
- Next, I’ll hook up a scan tool and pull all stored codes and freeze frame data. This can tell you if there’s more going on than just P067A.
- After that, clear the codes and take the truck for a short spin. If the code returns, you know it’s not a fluke.
- Then, I’ll pull the glow plug from cylinder 4 and bench test it-hook it up to a battery (carefully, since these get blazing hot in seconds). If it glows cherry red, it’s healthy. If not, it’s toast. I’ll also check resistance with a digital meter; if it’s out of spec, toss it.
- If the glow plug checks out, I use the scan tool to trigger the glow plug relay or timer, then check for battery voltage right at the plug’s connector. No voltage? Now, it’s time to dig into the control module, fuses, and relays.
- I never skip checking all related fuses and relays under load-a fuse that tests fine with no load can still fail you when you need it most.
- Last, if everything else looks good, I’ll trace the wiring back from the control module to the plug, looking for hidden breaks or shorts.
Here’s a pro-tip: When bench testing a glow plug, have someone nearby-these heat up quick and can burn you before you know it.
Common mistakes when fixing P067A code
The classic blunder I see? Folks assuming the glow plug can’t be the culprit just because the code mentions the ‘control circuit.’ Don’t be fooled-a dead glow plug will absolutely set this code. Another one is mixing up cylinder numbers and testing the wrong plug. Always double-check your engine’s firing order before diving in. Skipping simple stuff like connectors and fuses wastes a ton of time. And never just throw parts at the problem-test first, replace only what’s actually bad. Guesswork can get real expensive, real fast.
How serious is P067A
Don’t kid yourself-this is a code you want to deal with right away. A faulty glow plug circuit can make your diesel a bear to start, especially when it’s cold. Let it slide, and you’re asking for rough running, extra smoke, and potential damage to the engine or exhaust, like a clogged DPF or even injector trouble from unburned fuel. I’ve seen simple glow plug issues snowball into big repair bills. Take care of it now, and you’ll save yourself a lot of headaches down the line.
Repair options for P067A engine code
When it comes time to fix a P067A, here’s what I usually end up doing:
- Swap out the bad glow plug in cylinder 4.
- Repair or replace any damaged wiring or corroded connectors in the glow plug circuit.
- Replace the glow plug control module or timer if it’s not sending juice to the plug.
- Pop in new fuses or relays if any are blown or acting up.
I always recommend starting with the glow plug itself, since it’s the common troublemaker. If that doesn’t do it, then it’s time to dig deeper into wiring and the control module.
Conclusion
Bottom line: P067A means your engine’s computer has spotted a low voltage problem in the glow plug circuit for cylinder 4. This isn’t just a minor nuisance-ignore it, and you could be in for hard starts, poor running, and even pricey engine or exhaust repairs. In my experience, a bad glow plug is the most common cause, but I never rule out wiring or the control module. The best way forward? Start with a thorough inspection, test the plug, check your wiring, then move on to the more complex stuff. Don’t put this off-sort it out before you’re left stranded or facing a much bigger repair bill.
3927
6 minutes of reading