Oops... looks like the spiders padded through here
Add products to your cart and remove them from here Lets buy
B173d: Peugeot Work
Once the repair is complete:
The B173D code is rarely a software issue; it is almost always a physical electrical failure. Common causes include:
If you were looking for a different "b173d" reference (e.g., engine management, BSI, or ABS), please provide additional context (vehicle model/year or a full fault scan report). Otherwise, the above is the verified Peugeot diagnostic content for B173D.
The fault code B173D on a Peugeot indicates a failure to identify the mechanical or electronic key (or hands-free remote). This is typically an immobilizer-related issue where the car’s Built-in Systems Interface (BSI) cannot verify the key's security signal, often resulting in a "key not detected" message or a car that cranks but will not start. Immediate Troubleshooting Steps
Replace the Key Battery: A weak battery in your remote is the most common cause of intermittent recognition.
Try Your Spare Key: This helps determine if the issue is with a specific key or the car's receiver.
Perform a BSI Reset: If the system has "frozen," you can perform a soft reboot: Lower the driver’s window and open the bonnet.
Turn off all electronics, close the doors (do not lock), and remove the key.
Wait 3 minutes, then disconnect the battery terminal for 15 seconds.
Reconnect, wait another 10 seconds, then turn on the side lights and ignition without starting for a minute to allow the BSI to re-initialize.
Re-sync the Key: Turn the ignition to the "ON" position (without starting) and leave it for 2 minutes to allow the key and BSI to re-establish communication. Common Causes for B173D
Key Fob Failure: The internal transponder chip may be damaged or out of sync.
Faulty Antenna/Reader: The coil around the ignition barrel (for mechanical keys) or the interior aerial (for keyless systems) may be failing to pick up the signal. b173d peugeot work
Low Vehicle Battery: Peugeot electronics are highly sensitive to voltage drops; a dying car battery can cause "phantom" BSI faults.
Blown BSI Fuse: Check the 10A fuse inside the BSI unit (typically behind the glovebox), as a blown fuse here can cut power to the immobilizer circuit. Summary of Possible Fault Meanings Code Detail Likely Symptoms B173D:86 Identifier Invalid Key detected but not recognized as "correct" for this car. B173D:00 Identification Fault General failure to see any key signal at all.
In Peugeot (and broader PSA Group) vehicles, the fault code primarily identifies a communication or authentication failure within the vehicle's immobilizer system
. This code typically manifests as the car failing to recognize the key, preventing the engine from starting. Technical Breakdown of B173D The B173D code is logged when the Body Systems Interface (BSI)
—the car's central computer—detects an inconsistency or lack of signal from the transponder key or the immobilizer antenna. Prefeitura de Aracaju Primary Symptom
: The vehicle may display a "Key Not Detected" or "Immobilizer Fault" message on the dashboard. Engine Behavior
: In most cases, the engine will crank but fail to fire, or it may not crank at all as the BSI has disabled the starting circuit for security. Prefeitura de Aracaju Common Causes Weak Key Fob Battery
: A low battery in the key can weaken the transponder signal, making it difficult for the antenna to pick up the code. Immobilizer Antenna (Coil) Failure
: The ring antenna located around the ignition barrel (or near the Start button) may be faulty or disconnected. BSI Configuration or "Telecoding" Issues
: If the BSI has lost its synchronization with the keys—often after a major battery drain or jump-start—it may trigger this code. Wiring Faults
: Corrosion or breaks in the wiring between the immobilizer antenna and the BSI can interrupt the data flow. JustAnswer Recommended Troubleshooting Steps Try a Spare Key
: If the vehicle starts with a second key, the issue is likely a damaged transponder in the original key or a dead fob battery. Check Vehicle Battery Voltage Once the repair is complete: The B173D code
: Peugeot electronics are highly sensitive to voltage drops. A failing 12V vehicle battery can cause "phantom" BSI faults. BSI Reset (Soft Reset)
: Performing a "soft reset" (often involving disconnecting the battery following a specific sequence) can sometimes clear transient communication glitches. Professional Diagnostic
: If the code persists, a technician using Peugeot-specific software (like Diagbox) may need to perform "telecoding" to re-pair the keys to the BSI. French Car Forum
Understanding Peugeot Fault Code B173D: The Key Identification Error If you’ve hooked up a diagnostic tool like to your Peugeot and seen Fault Code B173D
, your car is likely refusing to start. This code is a common headache for Peugeot and Citroën owners, signaling a breakdown in the communication between your key and the car's security system. What Does B173D Actually Mean? Technically, B173D is defined as a
"Fault in identifying the mechanical/electronic key or hands-free remote control located in the reader" In simpler terms, your car’s Body Systems Interface (BSI) —the "brain" that manages electronics—is saying: "I see a key, but I don't recognize it as the right one"
. Because the immobilizer doesn't get the correct "handshake" signal, it prevents the engine from cranking or firing to protect against theft. Common Symptoms Non-starting engine: The car may not even attempt to crank. "Key Not Detected" messages:
Frequent alerts on the dashboard even when the key is in the ignition or reader. Occasional starting: The car might start fine one moment and fail the next. Top Causes and How to Fix Them
Diagnosis is key here; replacing parts blindly can get expensive quickly. Start with the basics:
Troubleshooting the Peugeot B173D Fault Code: When Your Steering Lock Acts Up
If you’ve hooked up a diagnostic scanner to your Peugeot and seen B173D pop up, you aren't alone. This code specifically points toward an "Internal fault in the electric steering column lock." While modern electronics make our cars safer, they can certainly make a Monday morning frustrating when the car refuses to acknowledge your key or won't start. What is the B173D Code?
On Peugeot models—particularly newer ones like the 308, 3008, or 5008—the steering column lock is an electronic module. Code B173D typically triggers when the car's computer (the BSI or BCM) detects that the lock mechanism isn't reaching its intended position (locked or unlocked) or there is an internal electrical failure within the module itself. Common Symptoms "Steering Lock Fault" message on the dashboard. The car refuses to start or the ignition won't turn on. If you were looking for a different "b173d" reference (e
A clicking sound from the steering column that doesn't result in a start.
Difficulty turning the steering wheel even when the key is detected. Potential Fixes and Steps to Take
The "Hard Reset":Sometimes the electronic modules just need a fresh start. Try disconnecting the battery for about 10–15 minutes. This can sometimes clear temporary "glitches" in the communication between the BSI and the steering lock.
Check Battery Health:Peugeots are notoriously sensitive to voltage drops. A worn-out battery can cause "ghost" codes across multiple systems. Ensure your battery is putting out at least 12.6V when the engine is off.
Inspect the Wiring:Before replacing expensive parts, check the wiring harness leading to the steering column. Look for loose connectors or signs of chafing. A simple loose pin can trigger a B173D code just as easily as a broken lock.
Module Replacement:If the code persists after a reset and the battery is healthy, the internal motor or the sensor inside the steering lock module may have failed. Because this is a security-linked part, replacements often require specialized coding to sync with your car's immobilizer system. Is it Safe to Drive?
If your car is already running, the steering won't suddenly lock while driving. However, if you see this message, avoid driving long distances and get it to a workshop immediately. Once you turn the car off, the faulty lock might refuse to disengage again, leaving you stranded.
Are you currently dealing with a B173D error? Tell us your car model and what happened leading up to the fault in the comments below!
Engine fault - Have your vehicle repaired: Peugeot / Citroën - klavkarr
The Peugeot fault code B173D primarily indicates a failure in identifying the key or remote control. This often manifests as an "Electronic Anti-Theft Faulty" message, resulting in a no-start condition because the immobilizer system cannot verify the key's signal. Understanding the Fault
Description: Fault in identifying mechanical/electronic key or hands-free remote control present in the reader (Identifier Invalid). Common Symptoms: The engine cranks but will not start.
"Economy Mode Active" or "Electronic Anti-Theft" messages on the dashboard.
The car may intermittently fail to detect the key when inside the reader. Immediate Troubleshooting Steps Electrical circuit fault: have your vehicle repaired
This guide is designed for mechanics, diagnostic technicians, or advanced DIYers. It covers the definition, technical explanation, common symptoms, causes, and a step-by-step repair procedure.