Duramax LB7 & LLY FICM Repair — Fuel Injection Control Module (2001-2005)
No-start, dead miss, or a Duramax that runs rough on half its cylinders? On an LB7 or LLY the injector drivers live in a separate FICM — we repair that module on the bench and send your original back.
Sending several modules? Add them all — one box, one return-shipping charge.
6.6L Duramax LB7 (2001-2004) and LLY (2004.5-2005) Fuel Injection Control Module — Silverado / Sierra 2500HD & 3500HD, Kodiak / TopKick
Duramax LB7 / LLY FICM Repair: the short answer
Duramax LB7 and LLY FICM repair is a mail-in, board-level repair of the Fuel Injection Control Module used on 2001-2004 (LB7) and 2004.5-2005 (LLY) 6.6L Duramax engines in Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks. The FICM generates the high-voltage, high-current signals that fire the injectors, and its driver and supply sections are the usual failure point. Auto Module Lab repairs your original module at our Arlington, Texas bench for $499.95 flat, typically in 3-5 business days, and ships it back to any US address.
How It Works
Three simple steps. Hundreds of mail-in jobs completed for shops, locksmiths, and DIY pros.
Pay & Get Address
Click "Order Now", pay securely online. We email shipping address + instructions within minutes.
Ship Your Module
Pack per the instructions and ship to Arlington. USPS goes to our PO Box; UPS and FedEx must use the street address. Customer pays shipping to us.
Receive in 1-2 Days
Work completed within 24 hours of receipt. Ships back next business day at the return speed you chose at checkout — standard to overnight. Tracking emailed.
What You Get
- Your original FICM opened, inspected and tested under load on our bench
- Board-level repair of the failed driver or supply section — not a swap
- Thermal cycling on intermittent faults, so a joint that fails hot is found
- Your module back with its data and configuration intact
- A written note of what we found and what we did
- An honest assessment first if the board is beyond economical repair — no charge for work we cannot deliver
Compatibility
Confirm your part matches one of the variants below before ordering. Not sure? Text us a photo and we'll verify.
We do not publish a FICM interchange table, because a wrong number on a page like this costs you a shipment. Text us a clear photo of your module's label along with your VIN and we confirm the exact part before you send anything — that check is free and takes minutes. The 2006 model year matters here: early-build 2006 trucks left the factory as LLY with a separate FICM, later 2006 builds are LBZ with the drivers inside the ECM, so your VIN and build date decide which service you actually need.
Engines
Applications
Module
Not this service
Will This Fix My Problem?
Honest answer: here's exactly what this service fixes — and what it doesn't.
Fixes:
- ✓No-start where the injectors are not being fired
- ✓A persistent dead miss on one or more cylinders that follows the module, not the injector
- ✓Rough running or a truck operating on a partial set of cylinders
- ✓Stored injector-circuit or injector-driver codes traced to the FICM
- ✓Lost communication with the FICM (U0105) where wiring and power check out
- ✓Intermittent running faults that appear once the engine bay is hot
Won't fix:
- ✗Mechanically failed injectors — the LB7 in particular is known for injector failure, and a bad injector is not a module fault
- ✗Fuel supply problems: lift pump, CP3, filters, air in the system, low rail pressure
- ✗Wiring, connector and ground faults between the FICM and the injectors
- ✗Mechanical engine faults — compression, timing, glow-plug system
- ✗A module with damage beyond economical repair — we tell you before charging
- ✗Emissions defeat of any kind. We do not offer DPF, EGR or DEF deletes and will not modify a module to disable emissions equipment.
What we repair on this module
Board-level faults, not symptoms. These are the specific failures our bench process targets.
Codes that commonly lead here
What each code means, and what it does not prove on its own.
A stored code is evidence, not a verdict. Every code below can also be set by wiring, connectors, grounds, power supply, or the component the module is trying to drive. Rule those out before you ship anything — or text us the codes and freeze-frame and we will tell you honestly whether the module is even a suspect.
| Code | Meaning | What it does not prove |
|---|---|---|
| U0105 | Lost communication with the Fuel Injection Control Module. | Also set by a broken or corroded harness, a bad ground, or loss of power to the module. Confirm the FICM is actually powered and its connector is clean before concluding the module is dead. |
| P0611 | Fuel Injector Control Module performance. | Points at the module's performance, not automatically at a failed board. Supply voltage and grounds influence this code, and so does an injector circuit loading the driver abnormally. |
| P062D | Fuel injector driver circuit performance, bank 1. | A shorted or failing injector on that bank can produce this code with a perfectly healthy driver. Injector resistance and the harness need ruling out first. |
| P062E | Fuel injector driver circuit performance, bank 2. | Same qualification as P062D — a driver fault and a failed injector on that bank look alike from the scan tool. |
| P0201-P0208 | Injector circuit, cylinders 1 through 8. | A single-cylinder code most often means that injector or its wiring. Multiple codes across a bank are what start pointing at the driver side rather than the injectors. |
Lost communication with the Fuel Injection Control Module.
Does not prove: Also set by a broken or corroded harness, a bad ground, or loss of power to the module. Confirm the FICM is actually powered and its connector is clean before concluding the module is dead.
Fuel Injector Control Module performance.
Does not prove: Points at the module's performance, not automatically at a failed board. Supply voltage and grounds influence this code, and so does an injector circuit loading the driver abnormally.
Fuel injector driver circuit performance, bank 1.
Does not prove: A shorted or failing injector on that bank can produce this code with a perfectly healthy driver. Injector resistance and the harness need ruling out first.
Fuel injector driver circuit performance, bank 2.
Does not prove: Same qualification as P062D — a driver fault and a failed injector on that bank look alike from the scan tool.
Injector circuit, cylinders 1 through 8.
Does not prove: A single-cylinder code most often means that injector or its wiring. Multiple codes across a bank are what start pointing at the driver side rather than the injectors.
Our bench process
What happens between your module arriving and it going back in the box.
- 1
Intake and visual inspection
Intake and visual inspection
Your module is logged against your order, photographed as received, and opened. We look for the things that decide whether a repair is even sensible: liquid ingress, corrosion tracking, previous repair attempts, physical damage to the connector or housing, and burnt or lifted components.
- 2
Power-up and communication test
Power-up and communication test
The module is powered on a bench harness and we confirm whether it comes up and communicates at all. A module that will not respond and one that responds but misbehaves are two different faults, and this is the step that separates them.
- 3
Fault localisation under load
Fault localisation under load
We test the sections that actually fail on these modules rather than guessing from the code you arrived with — supply rails, driver outputs, and the circuits feeding them, measured with the module doing work rather than sitting idle. Intermittent faults get thermal cycling, because a joint that reads fine cold is exactly the joint that opens hot.
- 4
Component-level repair
Component-level repair
Failed components are replaced and weak or cracked joints reworked. We repair the board you sent — this is not a swap-and-return. If a fault traces to something beyond economical repair, work stops here and you hear about it before anything is charged.
- 5
Data preservation and verification
Data preservation and verification
Where the repair touches memory or requires a programming step, your existing calibration and learned data are read first and restored afterwards, so the module goes back configured to your truck rather than blank.
- 6
Bench verification and return
Bench verification and return
The repaired module is retested on the bench, including the specific function that failed, and thermally cycled again before it is signed off. It ships back in protective packaging with tracking, at the return speed you chose at checkout.
Why repair your original?
The case for keeping the module that is already married to your vehicle.
It is already married to your truck
Your module carries your VIN, your calibration, and the values it has learned over its life. Repairing it keeps every one of those. A donor module carries someone else's, which is why used units so often need a programming session before the truck will run properly — an extra step, an extra cost, and an extra thing to go wrong.
A used module is the same age as yours
The realistic alternative to repairing a fifteen-year-old module is a fifteen-year-old module out of another truck, with an unknown service history and the same components approaching the same end of life. Repairing yours targets the part that actually failed instead of rolling the dice on someone else's.
The failure is usually smaller than the part
These modules do not generally fail as a whole. They fail at a driver, a supply section, or a set of joints — a repairable area on an otherwise sound board. Replacing the entire module to fix that is the most expensive way to solve a small problem.
You find out before you commit
We inspect and test before we repair, and if a board is beyond economical recovery we tell you rather than doing the work anyway. You are never charged for a repair we cannot deliver, which is not a promise a salvage-yard module comes with.
Repair vs used vs replacement
Four ways out of this failure, compared honestly.
| Path | What you actually pay for | Programming needed | Your data & tune | Main risk |
|---|---|---|---|---|
| Repair your original (this service) | Bench diagnosis and board-level repair of the module you already own. One flat price, one shipment each way. | None in most cases — it is still your module, still married to your truck. | Retained. VIN, calibration and learned values stay where they are. | A board damaged beyond economical repair. We assess first and tell you before charging. |
| Used / salvage module | A cheaper part up front, plus whatever it takes to make it work with your truck. | Usually yes — a donor module carries another VIN and another calibration. | Lost. You inherit the donor truck's configuration. | You are buying an unknown module of the same age and duty cycle. It can fail the same way, sometimes immediately. |
| Remanufactured unit | A rebuilt exchange unit, typically with a core charge and return of your original. | Usually yes, depending on how the reman was prepared. | Depends entirely on the supplier — ask before you buy. | Quality varies widely between remanufacturers, and your original is gone once the core ships. |
| New module through a dealer | A new part, dealer programming labour, and usually a tow if the truck will not run. | Yes — dealer setup and configuration to your VIN. | Configured fresh to your VIN by the dealer. | The highest-cost path, and dealer scheduling controls your downtime. |
- What you actually pay for
- Bench diagnosis and board-level repair of the module you already own. One flat price, one shipment each way.
- Programming needed
- None in most cases — it is still your module, still married to your truck.
- Your data & tune
- Retained. VIN, calibration and learned values stay where they are.
- Main risk
- A board damaged beyond economical repair. We assess first and tell you before charging.
- What you actually pay for
- A cheaper part up front, plus whatever it takes to make it work with your truck.
- Programming needed
- Usually yes — a donor module carries another VIN and another calibration.
- Your data & tune
- Lost. You inherit the donor truck's configuration.
- Main risk
- You are buying an unknown module of the same age and duty cycle. It can fail the same way, sometimes immediately.
- What you actually pay for
- A rebuilt exchange unit, typically with a core charge and return of your original.
- Programming needed
- Usually yes, depending on how the reman was prepared.
- Your data & tune
- Depends entirely on the supplier — ask before you buy.
- Main risk
- Quality varies widely between remanufacturers, and your original is gone once the core ships.
- What you actually pay for
- A new part, dealer programming labour, and usually a tow if the truck will not run.
- Programming needed
- Yes — dealer setup and configuration to your VIN.
- Your data & tune
- Configured fresh to your VIN by the dealer.
- Main risk
- The highest-cost path, and dealer scheduling controls your downtime.
We deliberately do not publish dealer or reman dollar figures — those move constantly and vary by region, and a made-up number would be worse than none. Call your dealer for a current quote and compare it against the flat price above.
LB7 injectors and the FICM are different problems — do not pay to fix the wrong one
The LB7 has a genuine reputation for injector failure, and that reputation causes real money to get spent in the wrong place in both directions. A dead miss can be an injector. It can equally be the driver that fires that injector. The distinguishing evidence is usually the pattern: a single cylinder that stays dead points at the injector or its wiring, while a whole bank going down, or a fault that comes and goes with underhood temperature, points at the module. Text us the codes, the cylinder numbers and any balance-rate data before you order and we will tell you honestly which one we think you have — including when the answer is that you do not need us.
See all Duramax module servicesShipping Instructions
These details are also emailed to you the moment your payment clears.
Ship your FICM only — the module itself, not the harness or brackets. It is mounted on the driver's side of the engine; unplug it, note which connector goes where, and box it with the connector protected. Include your codes and symptom notes, they genuinely change how we test. Return shipping is selected and paid at checkout — Standard $24.95, UPS 2-Day $54.95, or UPS overnight $94.95. Ship to PO Box 120241, Arlington TX 76012 (USPS) or 1009 Oakwood Ln # 120241, Arlington TX 76012 (UPS/FedEx).
What to include in your box
- Your Duramax FICM (module only — no harness, no brackets)
- A note listing your stored codes, which cylinders are affected, and whether the fault is hot, cold or constant
- Your VIN and model year — this is how we confirm LB7 vs LLY vs an early LBZ
- A printed order confirmation
- Your name, return address, and a phone number we can text
Ship to
Auto Module Lab
If shipping USPS
PO Box 120241
Arlington, TX 76012
If shipping UPS or FedEx
1009 Oakwood Ln # 120241
Arlington, TX 76012
Both shipping labels — to the lab and back to you — are purchased the moment you order. Your prepaid inbound label (already addressed) arrives by email; the return ships on the speed you chose at checkout.
Frequently Asked
Still have a question? Text us — replies in minutes.
How do I know whether it is the FICM or an injector?
Does my truck even have a separate FICM?
Will I get my own module back?
How long does the whole thing take?
What if my module cannot be repaired?
Do you do DPF, EGR or DEF deletes while it is on the bench?
Do I need to send the ECM too?
My truck is a work truck and I cannot have it down for a week. What are my options?
Does a repaired module need programming afterwards?
Is there a warranty on the repair?
Can a shop send these in on behalf of a customer?
Where does the work actually happen?
Related Services
Other bench services for the same brand or use case.
GM Cluster Upgrade + Mileage Program
Dead gauges, dim display, or want the higher-trim cluster? We upgrade and program your GM instrument cluster with the mileage and VIN carried over correctly.
GM BCM Standalone Clone (2000-2023)
Failed GM BCM taking your lights, locks, and anti-theft with it? We clone a working BCM to a replacement — VIN, mileage, theft system and all coding preserved.
GM Global A Virginize (Used ECM)
Used Global A ECM that SPS refuses to program? We reset it to a virgin, unmarried state so GM SPS / TIS2Web will take it to your VIN.
Where we serve Duramax LB7 / LLY FICM Repair
Mail-in means nationwide — we accept modules from all 50 states and DC from our Arlington, Texas lab. These states have their own shipping-and-transit page for this service:
Ready to ship?
$499.95 flat, typical 3-5 business day bench turnaround. Pay now, get the shipping address by email, drop it in the mail. Your module is back on your bench within a week.