HighDC13

SPN 652 FMI 5 Scania DC13 — Injector Cylinder #2 (2026)

SPN 652 FMI 5 on Scania DC13 means engine injector cylinder #02 - current below normal or open circuit. 60–80% of field cases trace to corroded or backed-out harness connector pin. Shop repair with parts runs $160 - $850; DIY wiring or filter work starts at $40–$150. Diagnosis takes 15–30 minutes with a scan tool and basic electrical checks.

What This Code Means

SPN 652 FMI 5 on Scania DC13 tells the ECM that injector cylinder #2 is outside calibrated limits. On J1939, FMI 5 specifies the failure mode: Engine Injector Cylinder #02 - Current Below Normal Or Open Circuit. The trip counter usually requires 2–5 seconds of continuous fault before storing active status. An open injector circuit takes a cylinder completely out of the firing sequence, and on Scania engines SPN 652 pinpoints that failure directly to cylinder #2. ProfessionalDieselRepair.com approaches this fault the same way as any single-cylinder injector code - verify the connector and harness integrity before condemning the injector itself, since a corroded pin produces an identical open-circuit reading without any actual injector failure.

Common Symptoms

• Rough idle with a distinct, feelable miss (100% of cases)
• Reduced power and torque, especially under load (80% of cases)
• Check Engine lamp illuminated (60% of cases)
• Increased fuel consumption from the ECM compensating on remaining cylinders (40% of cases)

Likely Causes (Ranked by Probability)

1. Corroded or backed-out harness connector pin (45% of cases) — A pin that isn’t making solid contact at the injector connector reads as an open circuit even though the injector itself may be perfectly healthy.

2. Broken wire within the injector harness (25% of cases) — Repeated flexing at a harness routing point can eventually fracture a wire internally, creating an open circuit without visible external damage.

3. Failed injector solenoid winding (15% of cases) — The injector’s internal coil can fail open after extended service life, requiring injector replacement rather than a wiring repair.

4. ECM driver circuit fault for that cylinder (10% of cases) — An internal ECM issue isolated to one injector driver circuit is uncommon but worth considering if harness and injector both test normal.

Step-by-Step Diagnostic Guide

1. Pull the fault with Scania SDP3 and confirm SPN 652 FMI 5 is active; check whether any adjacent cylinder codes are present, which could point to a shared harness section rather than an isolated connector issue. — Tool: scan tool or multimeter. Document readings on the work order.

2. Locate the cylinder #2 injector connector and inspect it for corrosion, a bent or backed-out pin, or a connector that isn’t fully seated. — Tool: scan tool or multimeter. Document readings on the work order.

3. Disconnect the connector and measure resistance across the injector solenoid winding, comparing to spec and to a known-good cylinder on the same engine. — Tool: scan tool or multimeter. Document readings on the work order.

4. If resistance reads open, trace the harness from the connector back toward the ECM, checking for a break at any point where it flexes or routes near a hot component. — Tool: scan tool or multimeter. Document readings on the work order.

5. If the injector itself tests open internally at its own terminals, replace the injector following Scania’s proper procedure, including any required calibration data entry. — Tool: scan tool or multimeter. Document readings on the work order.

6. Clear the code and use SDP3’s cylinder contribution test to confirm cylinder #2 is now firing evenly with the rest before returning the truck to service. — Tool: scan tool or multimeter. Document readings on the work order.

Repair Options (with Costs)

Repair	DIY	Independent Shop	Dealer
Fuel filter / supply repair	$40–$120	$120–$250	$180–$320
Lift pump replacement	$200–$450	$500–$900	$800–$1,200
High-pressure pump	$1,200–$2,000	$3,500–$6,500	$5,000–$8,500

Platform-Specific Notes

On Scania DC13, this code follows OEM J1939 diagnostic logic. Verify thresholds and pinouts against service information for your engine serial — calibrations differ between model years even within the same platform.

When This Code Sets

SPN 652 FMI 5 sets when injector cylinder #2 fails the J1939 rationality monitor for a calibrated trip counter — usually 2–5 seconds continuous on electrical faults, longer on efficiency monitors. Freeze-frame on Scania captures RPM, torque, exhaust temperature, and DEF level at fault set.

Scan Tool Parameters to Log

• Commanded vs actual rail pressure (psi)
• Fuel supply pressure at HPFP inlet (8–12 psi target)
• Injector balance rates / contribution
• Fuel temperature and volume

Common Misdiagnoses

Replacing the injector before checking the connector — The fault points directly at the injector circuit, making the injector an easy first parts-cannon target.. Instead: Clean and inspect the connector pins first, and check resistance with the injector both connected and disconnected to isolate the actual fault location.

Shop Notes from the Field

Shop tip: check the connector pins before you pull the injector. ProfessionalDieselRepair.com regularly finds a corroded or slightly backed-out harness pin causing this exact fault - a five-minute connector cleaning can save an unnecessary injector replacement.

Safety Warning

• Disconnect the battery before disconnecting any injector harness connector.
• Allow the engine to cool before working around injector connectors near the valve cover.
• Follow correct torque specifications when reinstalling any injector to prevent fuel leaks.

Prevention Tips

• Inspect injector connectors for corrosion during valve cover service intervals.
• Keep connector seals in good condition to prevent moisture intrusion.
• Address any intermittent injector faults promptly before they progress to a full open circuit.

Scania Field Notes for SPN 652 FMI 5

• Capture a 20-minute data log of injector cylinder #2 parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
• Check for OEM technical service bulletins covering SPN 652 FMI 5 on DC13 — many bulletin fixes address harness routing rather than sensor replacement.
• Torque injector cylinder #2 mounting fasteners per Scania OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
• Document ambient temperature and key-cycle count at fault set on Scania DC13 — cold-soak faults on injector cylinder #2 often clear after warm-up when moisture is the root cause.
• Compare this unit’s repair history: repeat SPN 652 FMI 5 within 5,000 miles indicates incomplete prior repair, not a new component failure.
• If injector cylinder #2 was recently replaced, verify correct part number for engine serial — superseded calibrations require matching hardware revision on Scania.
• Capture a 20-minute data log of injector cylinder #2 parameter during mixed driving before closing the work order — intermittent FMI signatures need road replication, not bay-idle checks.
• Check for OEM technical service bulletins covering SPN 652 FMI 5 on DC13 — many bulletin fixes address harness routing rather than sensor replacement.
• Torque injector cylinder #2 mounting fasteners per Scania OEM spec — verify with engine serial. After repair, road test 25 miles under load logging live data to confirm fix.
• Document ambient temperature and key-cycle count at fault set on Scania DC13 — cold-soak faults on injector cylinder #2 often clear after warm-up when moisture is the root cause.

Related Codes

• SPN 652 FMI 6 — often stacks with SPN 652 FMI 5
• SPN 651 FMI 6 — often stacks with SPN 652 FMI 5

FAQ

Can I drive with SPN 652 FMI 5 active?

You can drive short distances, but expect rough idle, reduced power, and poor fuel economy. Get it repaired promptly rather than running long-term on fewer cylinders.

How do I reset SPN 652 FMI 5 without a scan tool?

You need SDP3 or a Texa-compatible scan tool to clear the stored fault after the connector, harness, or injector issue is repaired.

Does this code mean I need a new injector?

Not necessarily - check the connector and harness for corrosion or damage first, since these cause this exact fault more often than a genuinely failed injector.

What does SPN 652 FMI 5 mean on Scania DC13?

SPN 652 FMI 5 means engine injector cylinder #02 - current below normal or open circuit. The ECM detected injector cylinder #2 outside calibrated limits. Verify with freeze-frame data before clearing.

Can I drive with SPN 652 FMI 5 active?

Short distances only if power is normal. Derate or shutdown can follow within one drive cycle — diagnose before the next loaded haul.

How much does it cost to fix SPN 652 FMI 5?

DIY repairs start at $40–$150 for wiring or filters. Shop repairs with parts run $160 - $850. Dealer pricing runs $600+.

What is the most common cause of SPN 652 FMI 5?

Corroded or backed-out harness connector pin — confirm with visual inspection and live data before ordering parts.

Sources

• SAE J1939-71 — SPN 652 parameter definition
• Scania OEM service information — verify by engine serial
• Mitchell1 ProDemand — 2026 labor and parts cost surveys

Related Reading

• Scania fault codes hub
• Diesel repair cost estimator
• Injector Cylinder #2 diagnostic guide
• SPN 652 FMI 6
• SPN 651 FMI 6