Has your BMW suddenly started behaving like it’s had a bit too much to drink? Perhaps it’s struggling to accelerate, idling roughly, or that pesky check engine light has decided to brighten up your dashboard? If you’ve had your car scanned and the mysterious “P1105 BMW fault code” has appeared, don’t panic! Today, we’re going to break down what this BMW fault code means, why the P1105 error happens, and what you can do about it—all explained in a way that makes sense even if you think a crankshaft is something to do with grumpy people.
At First Auto Centre, we’re proud to be a trusted BMW specialist in London with years of experience in BMW Diagnostics and BMW Repairs. We see plenty of bewildered BMW owners each week who’ve encountered the P1105 BMW fault code. By the end of this guide, you’ll understand what’s going on under your bonnet (that’s “hood” for our American friends) when this BMW P1105 code appears and feel more confident about getting it sorted.
What Does the BMW P1105 Fault Code Actually Mean?
Let’s decipher this automotive hieroglyphic known as the P1105 BMW fault code:
P = Powertrain (this relates to your engine, transmission, and associated bits)
1 = Manufacturer specific code (this is a BMW problem, not a universal one)
1 = Fuel and air metering
05 = The specific issue within that category
In plain English, the P1105 fault code on a BMW typically indicates an issue with the “Atmospheric Pressure Sensor Signal.” Now, what on earth is that when it’s at home?
The atmospheric pressure sensor (sometimes called a barometric pressure sensor) helps your car’s computer understand the air pressure outside. This information is crucial because air pressure affects how your engine performs—just like how you might find it harder to breathe at the top of a mountain where the air is thinner. Your BMW needs to know this information to adjust how much fuel to inject into the engine.
Symptoms: How You Know Your BMW Has a P1105 Fault Code Problem
When the BMW P1105 fault code appears in your vehicle’s diagnostic system, you might notice:
Your engine running roughly, especially when idling
Poor acceleration or hesitation when you press the accelerator
Reduced fuel efficiency (your wallet will notice this one!)
The engine management light (check engine light) illuminated on your dashboard
Your BMW going into “limp mode” in severe cases, which limits speed to protect the engine
It’s a bit like when you have a cold and can’t breathe properly—everything just feels off and sluggish.
Common Causes: What’s Triggering Your BMW’s P1105 Fault Code?
There are several potential culprits behind the P1105 BMW fault code appearing in your diagnostics:
Cause
Likelihood
Complexity to Fix
Faulty atmospheric pressure sensor
Very High
Moderate
Damaged wiring to the sensor
High
Moderate
ECU (Engine Control Unit) issues
Medium
High
Vacuum leaks in the intake system
Medium
Moderate
Software glitches in the engine management system
Low
Moderate
The most common issue is simply that the atmospheric pressure sensor itself has gone kaput. These sensors aren’t designed to last forever, and like any electronic component, they can fail over time. Sometimes, it’s just a matter of age—BMWs are fantastic cars, but even the best-engineered components wear out eventually.
The second most common issue is damaged wiring. Your BMW’s engine bay is a busy place with lots of heat, vibration, and potentially corrosive substances. Over time, the wires connecting the sensor to the car’s computer can become damaged, causing intermittent or complete signal loss.
Diagnosing the P1105 BMW Fault: Detective Work
Before you can fix anything, you need to be sure what’s caused the P1105 BMW fault code to appear on your diagnostic scanner. This is where professional car diagnostics come into play.
As a dedicated BMW specialist in London, our team at First Auto Centre uses specialised BMW Diagnostics equipment to accurately identify the root cause of your vehicle’s issues. Our BMW Diagnostic process for the P1105 BMW fault code involves:
Scanning the vehicle’s computer to confirm the P1105 BMW fault code and check for any additional related codes
Visual inspection of the atmospheric pressure sensor and its connections
Testing the sensor’s output signals using specialised equipment
Checking the wiring for continuity and proper resistance
Inspecting for vacuum leaks in the intake system
It’s a bit like solving a mystery—we need to gather all the clues before we can catch the culprit!
The Fix: Resolving Your BMW’s P1105 Fault Code
Once we’ve pinpointed the exact cause of your BMW’s P1105 fault code, the solution is often straightforward. As experienced BMW specialists, our BMW Repairs team can efficiently address these issues:
If it’s the Sensor Itself
Replacing the atmospheric pressure sensor is relatively straightforward for our BMW specialists. The sensor usually costs between £50-£150 for the part itself, depending on your specific BMW model. The labour typically takes about 30-60 minutes, as the sensor is usually accessible without major disassembly. Our BMW Repairs team has extensive experience with this particular fix.
If it’s Wiring Issues
Repairing or replacing damaged wiring requires more investigation and precision work. Our technicians will need to trace the wiring loom, identify the damaged section, and either repair or replace it. This might take 1-2 hours of labour, depending on how accessible the affected wiring is.
If it’s an ECU Issue
In rarer cases, the ECU itself might need reprogramming or, in very rare instances, replacement. This is more complex and would be part of a comprehensive car servicing process where we’d look at the entire engine management system.
If it’s a Vacuum Leak
Finding and fixing vacuum leaks can be a bit like finding a needle in a haystack, but our experienced technicians use smoke tests and other diagnostic methods to pinpoint the exact location before making repairs.
Preventing Future BMW P1105 Fault Codes: An Ounce of Prevention
While some component failures are inevitable over time, you can reduce the risk of encountering the P1105 BMW fault code again:
Regular BMW servicing is crucial for these precision-engineered vehicles. They need proper care from experienced technicians who understand BMW’s unique engineering. Book a service with our BMW specialist team to keep everything in tip-top condition.
Address warning lights promptly. That check engine light isn’t just for decoration!
Choose a qualified BMW specialist for all your maintenance needs. As a trusted BMW specialist in London, we understand the intricacies of BMW’s systems.
Keep engine components clean. Built-up dirt and grime can damage sensors and their connections.
Use quality parts for any replacements. Cheap alternatives might save money initially but often lead to more problems down the road.
The Cost: What to Expect When Fixing a BMW P1105 Fault Code
The total cost to fix a BMW P1105 fault code can vary depending on the underlying cause. At First Auto Centre, our BMW Repairs are competitively priced while maintaining high-quality service:
Repair Type
Estimated Cost Range
Time Required
Sensor replacement only
£120-£250
30-60 minutes
Wiring repairs
£150-£300
1-2 hours
ECU reprogramming
£200-£350
1-2 hours
ECU replacement
£500-£1,200+
2-4 hours
Vacuum leak repair
£150-£300
1-3 hours
These are rough estimates, and the actual cost will depend on your specific BMW model, the severity of the problem, and where you take your car for repairs. At First Auto Centre, we always provide a detailed quote before starting any work, so there are no nasty surprises.
According to a 2023 study by Warranty Direct, electrical sensor failures account for approximately 15% of all BMW repair claims, with the P1105 BMW fault code being among the more frequently reported issues, showing how common these atmospheric pressure sensor problems can be.
When to Seek a BMW Specialist?
While some car enthusiasts might be tempted to tackle this problem themselves, we’d recommend professional assistance from a qualified BMW specialist for BMW P1105 fault codes because:
Specialist BMW Diagnostics equipment is needed to properly test the sensor and its circuits
Access to the sensor can be difficult on some BMW models without the right tools
Electrical system diagnosis requires specific knowledge of BMW systems
Multiple potential causes mean you could waste money replacing parts that aren’t actually faulty
Our team at First Auto Centre has years of experience as a trusted BMW specialist in London, with expertise in BMW electrical systems. We can quickly pinpoint the exact issue, saving you time and money in the long run.
Conclusion: Don’t Let the BMW P1105 Fault Code Ruin Your Day
The P1105 BMW fault code isn’t the end of the world—it’s a fixable problem that, once addressed properly by qualified BMW specialists, should have your car running smoothly again. The atmospheric pressure sensor that triggers the P1105 fault code plays an important but relatively simple role in your engine’s management system, and issues with it are common enough that any good BMW specialist garage should be able to sort it.
If your BMW is showing the P1105 fault code, get in touch with us or book a BMW Diagnostics appointment online. As a dedicated BMW specialist in London, we’ll diagnose your BMW P1105 error and our BMW Repairs team will have you back on the road with a properly functioning vehicle before you know it!
Frequently Asked Questions About BMW P1105 Fault Codes
Can I still drive my BMW with a P1105 fault code?
While you technically can drive with the BMW P1105 fault code present, we wouldn’t recommend it for extended periods. Your BMW may run poorly, consume more fuel, and in some cases, enter limp mode which severely restricts performance. As BMW specialists, we’ve seen cases where ignoring this fault code led to more extensive (and expensive) BMW Repairs being needed later. Think of it like trying to run with a pebble in your shoe—you can do it, but it’s not good for you or comfortable!
Will a BMW P1105 fault code clear itself?
Sadly, no. Unlike that embarrassing thing you said at a party that everyone hopefully forgets, the P1105 BMW fault code won’t just disappear on its own. The underlying issue that triggered the P1105 error needs to be fixed, and then the code can be cleared using a proper diagnostic tool.
How is the atmospheric pressure sensor different from the MAP sensor?
Good question! The MAP (Manifold Absolute Pressure) sensor measures pressure inside your engine’s intake manifold, while the atmospheric pressure sensor measures the ambient air pressure outside. They work together to help your engine adjust for different conditions. It’s a bit like having one thermometer inside your house and another outside—both readings are useful for different reasons.
Does the P1105 fault code affect all BMW models equally?
The P1105 BMW fault code can appear across many BMW models, but it’s particularly common in 3 Series (E46, E90), 5 Series (E60), and X5 models from the early 2000s through the 2010s. According to BMW owner forums, the E90 3 Series seems especially prone to displaying the P1105 fault code, with some owners reporting multiple occurrences of this atmospheric pressure sensor issue.
Can weather changes trigger a BMW P1105 fault code?
Extreme weather changes rarely directly cause the P1105 BMW fault code, but they might make an existing atmospheric pressure sensor problem more noticeable. The sensor is designed to handle normal weather variations. However, very rapid changes in weather or extreme conditions might expose a sensor that was already beginning to fail, resulting in the P1105 code appearing on your BMW’s diagnostic system.
Is the BMW P1105 fault code related to the EGR valve problems BMWs sometimes have?
While they’re separate systems, problems with the EGR (Exhaust Gas Recirculation) valve can sometimes create symptoms similar to those caused by the P1105 BMW fault code. As experienced BMW specialists, we often find that both the atmospheric pressure sensor (P1105 fault) and the EGR valve need attention during a comprehensive engine service. When you bring your vehicle to our BMW specialist garage in London, our thorough BMW Diagnostics process ensures we identify all potential issues.
