OBD-II Diagnostic Trouble Code
P0613 — TCM Processor
P0613 means the transmission control processor failed an internal self-check, or the ECM detected a TCM processor fault. It's similar to P0606 but for the transmission controller. Depending on the vehicle, the processor may be in a standalone TCM or inside a combined powertrain module.
Severity 4/5
Truck-relevant
Stop within 50 mi
Severity
Stop within 50 mi
TCM Processor
Code
P0613
Category
Powertrain
Subsystem
Transmission
Truck-relevant
Yes
What this means for truckers
P0613 (TCM Processor) — transmission control module internal fault. Like P0606 (ECM), it's usually grounds + power issues before the module itself fails. Check ground straps first.
Before you replace parts — try this first
P0613 on the Transmission system is most often low voltage or poor tcm power and ground — 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
The transmission may go into a fail-safe or limp mode, locking in one gear, with harsh or no shifts. The check-engine or transmission warning light comes on. On automated or Allison transmissions you may see a do-not-shift indication.
Common causes
- CommonLow voltage or poor TCM power and ground ($100–$500)
- CommonInternal TCM failure ($1000–$3000)
- OccasionalCorrupted or outdated TCM software ($150–$450)
- OccasionalWater intrusion or corrosion at the TCM connector ($200–$2000)
How to fix
Check the batteries and voltage-drop-test the TCM power and ground circuits
When to use: First step
Check the TCM connectors for water and corrosion
When to use: Especially on frame- or transmission-mounted controllers
Reflash the TCM with the current software
When to use: When the supply is good
Replace and program the TCM
When to use: When the fault comes back after reflashing
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0670 — Glow Plug Control Module Circuit
- → P0671 — Cylinder 1 Glow Plug Circuit
- → P0672 — Cylinder 2 Glow Plug Circuit
- → P0673 — Cylinder 3 Glow Plug Circuit
- → P0674 — Cylinder 4 Glow Plug Circuit
Frequently Asked Questions
Can I drive with code P0613?
Drive with caution. P0613 is severity 4 — stop within ~50 miles. Most commercial diesel codes at this severity (turbo, fuel rail, transmission solenoid) can damage adjacent expensive components if left unrepaired. Get to a service location before highway-speed loads.
How much does it cost to fix P0613 on a commercial truck?
Total repair cost ranges $100–$3000 depending on the root cause. The cheapest fix is usually the first one listed below — Low voltage or poor TCM power and ground — 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 P0613 fail a DOT inspection?
P0613 typically doesn't fail an inspection on its own. Inspectors focus on safety items (brakes, steering, tires, lights, HOS). Transmission codes only become an issue if the truck has shifting problems severe enough to qualify as 'mechanical fitness' OOS. Fix to prevent escalation.
What's the difference between P0613 and related codes?
P0613 is closely related to: P0670 (Glow Plug Control Module Circuit), P0671 (Cylinder 1 Glow Plug Circuit), P0672 (Cylinder 2 Glow Plug Circuit), P0673 (Cylinder 3 Glow Plug Circuit). These codes share the same subsystem (transmission) 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 P0613 is set without the companions, the issue is more isolated.
How do I prevent P0613 from coming back after a repair?
For P0613 (TCM Processor), prevention centers on the transmission system. Service transmission fluid at the OEM interval (typically 150K–250K miles for HD autos). Don't skip the magnet/strainer inspection. After repair, perform an adaptive shift relearn with a scan tool (or drive 40+ miles for adaptive ECMs to relearn naturally).