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OBD-II Diagnostic Trouble Code

B1380 — PCM Pinion Factor Not Programmed

B1380 is a manufacturer-specific code meaning the powertrain control module's pinion factor (the tire size and axle ratio setting used to calculate vehicle speed) has not been programmed. Without it, computed speed and odometer values may be wrong or fall back to a default. It usually follows a PCM replacement or a configuration step that was never completed; the code number can mean something else on other OEMs.

Severity 2/5 Truck-relevant
Service soon
Severity
Service soon PCM Pinion Factor Not Programmed
Code
B1380
Category
Body
Subsystem
Speed
Truck-relevant
Yes
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What this means for truckers

Service this week on a Cummins X15, Detroit DD15, PACCAR MX-13. Not an immediate stop, but ignoring it usually leads to a more expensive fix downstream.

Before you replace parts — try this first

B1380 on the Speed system is most often pcm replaced or reflashed without the vehicle configuration being set — not a dead part. On commercial diesels especially, work these in order before spending money on parts:

  1. Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
  2. Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
  3. Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
  4. Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
  5. Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms

The speedometer and odometer read wrong or not at all. Speed-based functions such as cruise control, shift points and road speed limiting can misbehave, and an engine or service warning may be on.

Common causes
  • CommonPCM replaced or reflashed without the vehicle configuration being set ($100–$250)
  • OccasionalConfiguration lost because of a programming error or low voltage during programming ($100–$250)
  • RarePCM internal memory fault ($600–$1800)
How to fix
Program the correct tire size and axle ratio into the PCM with an OEM-level scan tool
When to use: First step whenever this code is present
Verify the actual tire size and axle ratio before programming
When to use: When tires or the axle were changed from factory spec
Replace and fully program the PCM
When to use: When the setting will not store or keeps getting lost
Affects most

No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.

Related

Frequently Asked Questions

Can I drive with code B1380?
B1380 is severity 2 — service this week. Not an immediate stop, but ignoring it usually compounds the problem. Most common cause for this code is a worn sensor or minor performance fault that won't strand you today but will get more expensive the longer you wait.
How much does it cost to fix B1380 on a commercial truck?
Total repair cost ranges $100–$1800 depending on the root cause. The cheapest fix is usually the first one listed below — PCM replaced or reflashed without the vehicle configuration being set — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will B1380 fail a DOT inspection?
B1380 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between B1380 and related codes?
B1380 is closely related to: B1318 (Battery Voltage Low), B1342 (EEPROM Memory Failure). These codes share the same subsystem (speed) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only B1380 is set without the companions, the issue is more isolated.
How do I prevent B1380 from coming back after a repair?
For B1380 (PCM Pinion Factor Not Programmed), prevention centers on the speed system. Inspect wheel speed sensor wiring at PM (rodents love it). Keep ABS tone rings clean.

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