P1635 Mercury Code - Tire / Axle Ratio Out of Acceptable Range
Quick Answer
The All-Wheel Drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. Common causes include Incorrect tire size, Incorrect axle ratio, Incorrect Vehicle ID block configuration parameters. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1635 Mercury indicates Tire / Axle Ratio Out of Acceptable Range.
- Common causes
- Common causes include Incorrect tire size, Incorrect axle ratio, Incorrect Vehicle ID block configuration parameters.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P1635 Mercury Description
What are the Possible Causes of the DTC P1635 Mercury?
- Incorrect tire size
- Incorrect axle ratio
- Incorrect Vehicle ID block configuration parameters
How to Fix the DTC P1635 Mercury?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
After a new Powertrain Control Module (PCM) has been installed, the Vehicle Identification (VID) block has to be programmed into the PCM.
There is a Factory Service Bulletin for the following Mercury models:
2008-2011 Mercury Grand Marquis / Marauder
2008-2011 Mercury Mariner
2008-2011 Mercury Milan
2008-2009 Mercury Montego
2008-2010 Mercury Mountaineer
2008-2009 Mercury Sable
Mercury Factory Service Bulletin OBDII Code P1635
There is a Factory Service Bulletin for the 2002 Mercury Mountaineer:
2002 Mercury Mountaineer Factory Service Bulletin OBDII Code P1635
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P1635 Mercury code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P1635 Mercury code?
Need more information on how to fix the P1635 Mercury code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1635 Mercury code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P1635 Mercury Code
What does the OBDII code P1635 mean for a Mercury vehicle?
Code P1635 indicates that the Tire/Axle Ratio is out of the acceptable range, meaning the vehicle's tire size or axle configuration may not match factory settings.
What are the common symptoms of code P1635 in Mercury vehicles?
Symptoms include inaccurate speedometer readings, reduced fuel efficiency, and potential transmission shifting issues.
What causes the P1635 code on Mercury vehicles?
The code is typically caused by incorrect tire sizes, changes to the axle ratio, or a malfunction in the Powertrain Control Module (PCM).
Can aftermarket modifications trigger the P1635 code?
Yes, installing non-standard tire sizes or changing the axle ratio without reprogramming the PCM can trigger this code.
How is the P1635 code diagnosed?
A technician will verify the tire size and axle ratio, inspect the PCM for software errors, and check for wiring issues related to the speed sensor.
How do you fix the P1635 code in a Mercury vehicle?
Repairs may include recalibrating the PCM, replacing tires with factory-specified sizes, or correcting axle ratio mismatches.
Can driving with the P1635 code cause damage to the vehicle?
While it may not cause immediate damage, prolonged driving with this code can lead to transmission wear and reduced performance.
Does the P1635 code affect the vehicle's speedometer?
Yes, it can cause inaccurate speedometer readings due to mismatched tire or axle ratios impacting the speed calculation.
Can a faulty speed sensor cause the P1635 code?
While less common, a malfunctioning speed sensor can contribute to this code by sending incorrect data to the PCM.
Is reprogramming the PCM always required to fix the P1635 code?
Reprogramming is necessary if tire or axle modifications were made, but it may not be required if the issue is related to sensor or wiring faults.
Discuss the causes and fixes for P1635 Mercury OBDII Code
Code P1635 Mercury comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
