U1058 — SCP (J1850) Invalid or Missing Data for Transmission / Transaxle / PRNDL #

Note: The description for DTC U1058 may vary depending on the vehicle manufacturer (OEM).

• Ford: SCP (J1850) Invalid or Missing Data for Transmission/Transaxle/PRNDL
• Lincoln: SCP (J1850) Invalid or Missing Data for Transmission/Transaxle
• Mazda: Invalid or Missing Data for PRNDL
• Mercury: SCP (J1850) Invalid or Missing Data for Transmission/Transaxle/PRNDL

Summary of code U1058 #

Diagnostic Trouble Code (DTC) U1058 indicates that the vehicle’s communication network—specifically the SCP (Standard Corporate Protocol) using J1850—has detected invalid or missing data related to the Transmission/Transaxle or the PRNDL (Park, Reverse, Neutral, Drive, Low) switch. In plain terms, this code means that the relevant module (often the Powertrain Control Module, or PCM) is not receiving the expected data from the transmission or PRNDL system. This can point to a communication fault, a wiring issue, or a malfunctioning sensor/controller. U-codes are network communication faults, not direct component failures, so diagnosis must focus on data flow and module connectivity. Left unaddressed, this code can impact gear selection display, shifting logic, and safety features.

Common symptoms for code U1058 #

When U1058 is present, the vehicle may demonstrate a range of symptoms. Many are subtle, but some can affect drivability or safety. The most frequent include:

• PRNDL indicator (gear selector display) not functioning or displaying incorrect gear
• Transmission stuck in one gear (limp mode)
• Malfunction Indicator Lamp (MIL) or “Check Engine” light on
• Communication-related warning messages on the dashboard
• Intermittent or total loss of transmission data on scan tools
• Shifting delays or harsh shifting

Probable causes for code U1058 #

The most frequent causes for U1058 are network or wiring issues, but other factors can trigger this code. Here they are, in order of likelihood:

1. Faulty or loose wiring/connectors between the transmission module and the PCM
2. Failure of the PRNDL switch (range sensor)
3. Communication bus (SCP/J1850) interruptions or shorts
4. Transmission Control Module (TCM) or related module malfunction
5. Software issues or need for reprogramming
6. Blown fuses or poor power/ground connections

Step-by-step diagnosis for code U1058 #

Diagnosing U1058 requires a systematic approach focused on the vehicle’s communication network and related components. Here’s how an expert technician would proceed:

• 1. Confirm the code and check for other DTCs using an advanced scan tool. Note any related codes (especially U-codes).
• 2. Inspect the PRNDL function—does the gear display match the actual shifter position?
• 3. Visually inspect wiring and connectors between the transmission, PRNDL switch, and PCM for signs of corrosion, pin damage, or looseness.
• 4. Test the J1850 (SCP) network integrity using a scope or suitable scan tool to check for proper signal and communication.
• 5. Check power and ground circuits at the TCM and PRNDL switch with a multimeter.
• 6. Use live data to monitor PRNDL and transmission module communication—look for missing, implausible, or intermittent data.
• 7. If wiring and power/ground are good, attempt to reflash or update relevant modules if software issues are suspected.
• 8. As a last step, replace the PRNDL switch or TCM if confirmed faulty.

Possible repairs for code U1058 #

The repair depends directly on the root cause found during diagnosis. Here are the most common fixes:

• Repair or replace damaged wiring or connectors in the SCP (J1850) network or between modules
• Replace the PRNDL switch (range sensor) if found faulty
• Repair or replace the Transmission Control Module (TCM) if defective
• Reprogram or update module software as per OEM technical service bulletins (TSBs)
• Replace blown fuses and clean or secure ground points

Is it safe to drive with code U1058? #

In most cases, it is NOT recommended to drive long-term with code U1058 present. While the vehicle may operate, the transmission may be stuck in a default gear (limp mode), display the wrong gear, or fail to engage gears properly. This can make driving unpredictable and potentially unsafe, especially if the PRNDL display is incorrect. If you must move the vehicle, do so cautiously and have it inspected by a qualified technician as soon as possible.

Vehicles most commonly affected by code U1058 #

U1058 is most frequently seen on vehicles using the Ford SCP (J1850) communication protocol. These include several models from the late 1990s to mid-2000s, though similar codes may appear in other brands that use J1850 networking.

• Ford Explorer, Expedition, F-150, Taurus
• Lincoln Navigator, Town Car
• Mercury Mountaineer, Sable
• Mazda Tribute (certain years/models)

Common mistakes and best practices with code U1058 #

With U1058, the biggest error is rushing to replace expensive modules without checking simpler causes. Here’s what to avoid and what to focus on:

• Do not replace the transmission or TCM first—always check wiring, connectors, and PRNDL switch first
• Don’t ignore possible software issues—consult OEM TSBs for updates
• Use a scan tool capable of reading network data to avoid missing communication faults
• Always inspect power and ground connections before condemning modules
• Document all findings and steps taken for accurate troubleshooting and future reference

FAQ for code U1058 #

Q: Can a weak battery or poor ground trigger U1058?
A: Yes—low voltage or ground issues can disrupt communication and cause U-codes like U1058. Always test battery and charging systems as part of your diagnosis.

Q: Does clearing the code make it go away permanently?
A: No—U1058 will return if the underlying communication or wiring problem is not fixed. Clearing the code can help verify if repairs are effective, but it is not a solution by itself.