OBD-II Diagnostic Trouble Code
C2106 — Pressure Loss / Tire Pressure Low (TPMS)
C2106 indicates tire pressure loss or low tire pressure detected by the TPMS. The module saw one or more tires below the warning threshold. Definitions vary by OEM.
Severity 2/5
Truck-relevant
Service soon
Severity
Service soon
Pressure Loss / Tire Pressure Low (TPMS)
Code
C2106
Category
Chassis
Subsystem
Brakes
Truck-relevant
Yes
What this means for truckers
C2106 (Tire Pressure Low / TPMS) — one or more tire pressures are below threshold. Check all tires with a quality gauge. On commercial trucks with multi-tire setups (dual rear wheels), TPMS sensors can fail individually. Sensor replacement requires removing the tire from the rim ($80-180 per sensor + mount/balance).
Before you replace parts — try this first
C2106 on the Brakes system is most often low tire pressure — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- 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.
- 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.
- 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.
- 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.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
TPMS lamp on, possible pulling or poor handling, increased tire wear and fuel use.
Common causes
- CommonLow tire pressure ($0–$50)
- CommonTire puncture or bead leak ($30–$200)
- OccasionalFaulty valve stem ($30–$150)
- OccasionalFailed TPMS sensor ($80–$250)
How to fix
Check and inflate tires to placard pressure
When to use: First step
Inspect for punctures and bead leaks
When to use: Pressure drops again
Repair or replace the valve stem
When to use: Stem leak
Replace the TPMS sensor and relearn
When to use: Sensor reads wrong
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 C2106?
C2106 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 C2106 on a commercial truck?
Total repair cost ranges varies depending on the root cause. The cheapest fix is usually the first one listed below — Low tire pressure — 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 C2106 fail a DOT inspection?
C2106 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 C2106 and related codes?
C2106 is closely related to: C2107 (Tire Pressure Monitoring System (TPMS) Battery Low). These codes share the same subsystem (brakes) 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 C2106 is set without the companions, the issue is more isolated.
How do I prevent C2106 from coming back after a repair?
For C2106 (Pressure Loss / Tire Pressure Low (TPMS)), prevention centers on the brakes system. Clean wheel speed sensors at every brake service. Inspect tone rings for cracks or rust. Keep ABS sensor harnesses away from chafe points. Don't drive through deep water that can flood the rear wheel-speed sensor connectors.