P2609 on RAM: How to Diagnose & Fix
Intake Air Heater System Performance
1 RAM model · 1 documented issue · 1 critical · $300-$18,000 repair
P2609 on RAM by model: symptoms, diagnosis and fix
The intake grid (air) heater warms incoming air for cold starts and carries up to ~200 amps through a small threaded stud/bolt secured by a 10mm nut on the intake plenum. Over years of high-current heat cycling the bolt/nut connection deteriorates, arcs, and can break loose. Because it sits directly above the intake runner, gravity pulls the heavy steel stud straight into cylinder #6, destroying the piston, valves, and cylinder head, often the entire engine. Banks Power has documented 200+ failures, some at as little as 40,000 miles. Stellantis has NOT recalled the grid heater assembly itself (a separate 2021-2022 relay recall Y08/Y76 addressed sticking relays, not the bolt).
Common Symptoms
- Loud engine knock / metallic clatter
- Sudden power loss
- Rough running or misfire on cylinder 6
- Loose grid heater power terminal
- Check engine light with grid heater codes
- Hard cold starts
How to Fix
Do the preventive 'wiggle test': with the engine off, grab the external power terminal (10mm bolt) and try to move it; any movement means the internal stud is loosening and needs immediate attention. Best fix is to replace the stock grid heater with a redesigned unit that eliminates the internal bolt, such as the BD Diesel Killer Grid Heater upgrade kit (PN 1041520, fits 2007-2024), or install a grid-heater delete/relocation plate (Fleece/Pusher) if legal in your area. Genuine Cummins intake air heaters (e.g., 3970000 / 3970001) are direct replacements but retain the original design.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- BD Diesel 1041520 Killer Grid Heater Upgrade Kit
Follow BD instructions and verify exact vehicle/engine before purchase.
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Sources for this issue (3)
P2609 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2609 mean on a RAM?
P2609 stands for "Intake Air Heater System Performance." A rationality/performance code: the PCM monitors the overall intake air heater system (via intake air temperature response after the heater is commanded on) and determines the system is not heating intake air as expected, even though no specific circuit fault is present. On RAM it is documented across 1 model: 2500.
What are the most common causes of P2609?
The most common causes of P2609 are: Weak or partially failed intake air heater element(s), Faulty intake air heater relay, Intake air temperature sensor inaccuracy, High resistance in the heater power circuit, Low system voltage to the heater. The specific cause varies by vehicle.
How much does it cost to fix P2609 on a RAM?
Published repair estimates on RAM range from $300 to $18,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P2609 on a different make?
View P2609 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.