Quick answer
P2609 on a 6.7 Cummins: What the Code Means and Why Not to Ignore It
Published · Updated · 3 min read
The short answer
P2609 is the intake air heater (grid heater) circuit. On a 6.7 Cummins it can be the relay, the heater grid or the small bolt and nut that carry its current inside the intake. Inspect the grid heater hardware before you replace only the relay: if that bolt breaks off, it can be pulled into a cylinder.
What the code means
The 6.7 Cummins warms the incoming air for cold starts with a grid heater in the intake after the turbo, switched by a high-current relay. P2609 says the system is not working as commanded, so the cause can be anywhere on that path. verified Ram's own service note for 2012-2016 trucks with P2609 or P0542 (9003585) says to replace the heater grid and the relay as a set and to inspect the cable between them for overheating. verified
Why it matters more on this engine
- The bolt or nut33
- A cylinder, piston or valve21
- Fire or smoke14
- The relay12
- The code P2609 by name8
Keyword-matched; one complaint can mention several. A count of reports, not a failure rate. Sets of our 6.7 Cummins articles, pulled 2026-09-12 and 2026-10-10.
The current runs through a nut and bolt that sit inside the intake. Heat and arcing wear them until they break, and the intake pulls them into a cylinder, most often number 6. verified That is why two thirds of these complaints mention the bolt or nut and 21 mention a cylinder, piston or valve.
One 2017 Ram 2500 owner told NHTSA in 2023 that P2609 came on at 83,015 miles, a new relay cleared it, and a week later the code was back. The bolt on the grid heater plate turned out to be broken, but still stuck to the plate, not yet in the engine (complaint 11516357). aggregated
The relay failed, melted a bolt and attached nut that fell into the intake manifold. Owner of a 2017 Ram 3500 with P2609, 2025. The engine was destroyed. NHTSA complaint 11645067
What to do
- Do not just clear it and drive. Have the intake horn removed and the grid heater terminal bolt and nut inspected for burning, looseness or breaks.
- Replace the grid and relay together if either has failed, as Ram's note says, and check the cable between them.
- On a 2021-2023 truck, run the VIN: recalls 21V-163, 21V-798 and 23V-060 cover a heater relay that can short and start a fire with the ignition on or off. verified
What it costs
A bolt retention kit lists at about $220. Caught at the code, one 2017 Ram owner put the repair at about $3,000 in 2025 (complaint 11657202); after the bolt reached a cylinder, a 2016 Ram 2500 owner put it at over $10,000 in 2023 (complaint 11506481). aggregated
Quick questions
Can I drive with a P2609 code?
The truck usually runs, and in warm weather it may start normally. The risk is the grid heater bolt: until someone has looked at it, every mile is a chance for it to break off into the engine. Get it inspected soon.
Is P2609 just the grid heater relay?
Sometimes. But a relay that fails can also overheat the terminal, and owners describe the code coming back after a new relay because the bolt was the real problem. Inspect both.
Does the 2019 and newer 6.7 Cummins have the same problem?
Yes. Owners describe the same bolt failure on 2019 and newer trucks, and 2021-2023 trucks also have relay fire recalls.
The full story of the grid heater, with the 2007.5-2018 and 2019+ trucks: 6.7 Cummins problems · 2019-2024 Ram 6.7 Cummins problems.
Sources. NHTSA owner complaints database (US government public domain), the 6.7 Cummins sets of our Cummins articles; quotes are taken from complaint narratives with capitalization normalized. Ram service note 9003585 from NHTSA's manufacturer communications index; NHTSA recall records 21V-163, 21V-798 and 23V-060. Grid heater mechanism from our platform records. Part prices are list prices at the time of publication. Torque Index aggregates and cross-checks public information, takes no paid placement and does not provide repair or inspection services.