Hey everyone,

Timeline of Events:

• Purchase and Delivery:I test-drove the truck, checked everything, and it worked flawlessly.
  The seller delivered it to my house (about an hour drive) with no problems.

• First Drive to DMV:I drove the truck to the DMV with no issues, and the seller followed me in his car.
  After completing the registration and paying the seller, I started driving home. Within five minutes, the tachometer stopped working, and when I tried restarting the truck, the PATS security light blinked rapidly, and the truck wouldn’t start.
  I called the seller, who returned to help me troubleshoot. We went through all the PATS override steps (e.g., leaving the key in the ignition for 10 minutes), but nothing worked. Eventually, I had to get the truck towed to the dealership.

• First Tow:At the dealership, the truck started right up without any issues. Thinking it might’ve been a fluke, I drove it back home.

• Next Day:The next morning, I tested the 4x4 system (which worked fine), but the tachometer died again while running. This time, the truck wouldn’t start at all, with PATS activating and the dash showing dashes in the mileage.
  After leaving it for a while, it randomly started working again later that afternoon after i had the key in the on position for awhile.

• Current Issue:Now the truck consistently won’t start. Every time, the mileage shows dashes, the tachometer briefly pulses but remaines dead when putting key to on position, and the PATS security light blinks rapidly when I insert the key.

What I’ve Tried So Far:

• Fuses and Relays:I initially checked all the fuses related to the PCM, RCM, and ignition but found no issues.
  After going through every single fuse one by one, I found the instrument cluster battery feed fuse was blown. I replaced it, but the issue persists.

• Key and PATS Concerns:The truck did not come with a master key, which I originally thought was the problem. However, since the truck starts occasionally, I think the issue might not be the key itself.
  A locksmith came out and confirmed that the dashes in the mileage suggest an ECU or communication problem, but he doubted the ECU was dead since the truck sometimes starts.

• Battery and Alternator:The battery is strong, with consistent voltage, and all connections are clean and tight.

• Instrument Cluster:When the truck doesn’t start, the tachometer dies, and the odometer only shows dashes. This seems to be a major symptom of the issue.

• Error Codes:
  A scan revealed multiple communication faults, including:U0100: Lost communication with PCM.
  B1317/B1318: Battery voltage too high/too low.
  B1342: RCM (Restraint Control Module) fault.
  U1900: CAN network communication error.

Additional Notes:

• The truck has no history of major electrical issues (according to the seller).

• This issue is entirely random and doesn’t seem to be triggered by specific driving conditions.

• I previously owned a Ranger for 9 years, which randomly got totaled by a uninsured drunk driver while parked on the street and I lost it. I’m excited to be a Ranger owner again. But this issue is frustrating and a little depressing and makes me worried about the timing of this purchase.

Questions for the Community:

• Has anyone experienced a similar combination of PATS activation, dashes in the mileage, and intermittent starting issues?

• Could this be a fault in the instrument cluster, PCM, or CAN bus wiring?

• Is it possible that proximity to another car’s fob caused some sort of interference or corruption in the PATS system?

• Could this be resolved by programming a new key or resetting PATS with dealer-level tools?

• Any advice on next steps? I’d like to avoid throwing parts at the problem without isolating the root cause.