U1173 — SCP (J1850) Invalid or Missing Data for Remote Button Control #

Note: The wording of this code may vary depending on the manufacturer.

• Ford: SCP (J1850) Invalid or Missing Data for Remote Button Control
• Lincoln: SCP (J1850) Data Error: Remote Button Control
• Mercury: SCP (J1850) Lost Communication with Remote Button Module

Summary of code U1173 #

The U1173 diagnostic trouble code (DTC) indicates that the vehicle’s main control module has detected invalid or missing data from the Remote Button Control over the SCP (Standard Corporate Protocol) J1850 communication network. This network is a communication pathway that lets different modules (computers) inside your car “talk” to each other, sharing vital information to keep everything running smoothly. When this code pops up, it means the data expected from the remote control buttons (such as those for keyless entry or steering wheel controls) is either corrupted or not arriving at all. This can lead to malfunctions in convenience features or even impact system security. While it’s rarely an emergency, ignoring this code can lead to bigger headaches if other modules begin to lose communication too.

Common symptoms for code U1173 #

If your vehicle is storing U1173, you may notice some annoying, yet subtle issues. These typically revolve around remote-controlled functions not working as expected. Sometimes, the symptoms are so mild they go unnoticed until you try to use a specific feature.

• Remote key fob not locking or unlocking doors
• Steering wheel audio or cruise control buttons unresponsive
• Warning lights for keyless entry or security systems
• Intermittent or complete loss of remote-related functions
• No response from trunk/hatch release on remote

Likely causes of code U1173 (in order of frequency) #

Several factors can disrupt data flow on the SCP (J1850) network, but some culprits show up more often than others. Here are the most common causes, ranked by how frequently they’re seen in the field:

1. Faulty Remote Button Control Module — The module itself may have failed or is sending corrupted data.
2. Wiring or Connector Issues — Damaged, corroded, or loose wiring/connectors between the Remote Button Control and other network modules.
3. SCP (J1850) Network Problems — Short circuits, open circuits, or interference in the data bus wiring affecting communication.
4. Software Glitch — Outdated or corrupted software in one of the connected modules.
5. Low Battery Voltage — Weak or unstable battery voltage can disrupt module communication.

Step-by-step diagnosis for code U1173 #

Diagnosing U1173 is a bit like following a trail of breadcrumbs through your vehicle’s electronic nerve center. Here’s a proven approach used by master technicians:

• Scan for additional codes: Use a professional scan tool to check for related U-codes or B-codes (body control), which might provide more clues.
• Check remote button operation: Test all remote buttons on the fob and inside the vehicle (steering wheel, trunk release, etc.).
• Inspect wiring and connectors: Look for pinched, corroded, or disconnected wiring/connectors at the Remote Button Control and along the SCP (J1850) network.
• Test the Remote Button Control Module: Use a multimeter and scan tool to verify module power, ground, and data signal integrity.
• Check battery and charging system: Low voltage can corrupt module data; ensure battery and alternator are within spec.
• Update or reprogram software: If all hardware checks out, look for available OEM software updates for the affected modules.

Possible repairs for code U1173 #

Once you’ve pinpointed the cause, the fix should directly address the issue. Here are the most effective repairs linked to the causes above:

• Replace faulty Remote Button Control Module
• Repair or replace damaged wiring/connectors on SCP (J1850) network
• Clean and secure all module connectors
• Update or reflash module software to latest OEM version
• Replace or recharge weak battery; repair charging system as needed

Is it safe to drive with code U1173? #

Yes, but with limitations. U1173 usually does not affect core driving functions like engine or brakes. However, you may lose access to remote entry, steering wheel controls, or other convenience features. If other modules begin to lose communication, more serious electrical symptoms could arise. It’s wise to address this code soon, especially if you rely on remote features for security or daily use.

Vehicles most commonly affected by code U1173 #

This code is most often encountered in vehicles from the Ford family that use the SCP (J1850) data bus for communication between control modules. While it can technically appear on any vehicle using this protocol, it’s rarely seen outside of these brands.

• Ford F-150, F-250, Expedition, Explorer
• Lincoln Navigator, Aviator, Town Car
• Mercury Mountaineer, Grand Marquis
• Some older Ford/Lincoln/Mercury models (1996–mid-2000s)

Common mistakes & best practices for U1173 #

When dealing with communication codes like U1173, it’s easy to chase your tail or overlook simple issues. Here’s what experienced techs have learned:

• Don’t replace the Remote Button Control Module without first checking wiring and power/ground (it’s often a connection issue!)
• Always scan for additional codes — they can reveal underlying network or module faults
• Don’t ignore battery voltage; weak batteries are a common source of communication glitches
• Use only OEM-compatible scan tools for diagnosis and reprogramming

Quick FAQ for code U1173 #

Still have questions? Here are the answers to what drivers and techs ask most:

• Q: Will clearing the code fix the problem?
  A: Clearing the code may temporarily turn off the warning light, but unless the root cause is fixed, U1173 will return.
• Q: Can a dead remote battery cause U1173?
  A: No. U1173 relates to the vehicle’s internal communication network, not the battery in your key fob. However, a weak car battery can cause similar communication errors.