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OBD-II Code

P1740

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$250–$4,500

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

$250 (solenoid pack DIY + fluid on a 41TE) to $4,500 (full rebuild of a 545RFE at a transmission shop).

P1740 on Chrysler/Mopar is TCC or OD Solenoid Performance — the TCM (transmission control module) commanded the torque converter clutch (TCC) lockup or the overdrive (OD) solenoid to engage and the resulting input/output shaft speed ratio didn't match the expected value, indicating slip, sluggish engagement, or solenoid failure.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP1740 on Chrysler/Mopar is TCC or OD Solenoid Performance — the TCM (transmission control module) commanded the torque converter clutch (TCC) lockup…

P1740 on Chrysler/Mopar is TCC or OD Solenoid Performance — the TCM (transmission control module) commanded the torque converter clutch (TCC) lockup or the overdrive (OD) solenoid to engage and the resulting input/output shaft speed ratio didn't match the expected value, indicating slip, sluggish engagement, or solenoid failure. This is one of the most common transmission codes on the Aisin/A604/A606/41TE/42LE/545RFE family.

Cheapest-first ladder

  1. scan live transmission data and watch TCC slip RPM at highway speed — a healthy TCC should lock within 50-100 RPM of true 1:1 lockup; persistent slip of 200+ RPM is the converter or its lockup clutch failing.
  2. Check transmission fluid level and condition first (Chrysler ATF+4 specifically — substituting Dexron or generic ATF will set this code by itself).
  3. Burned/dark fluid means the clutches inside the transmission are already cooking; a fluid change won't save it.
  4. Drop the pan, inspect the solenoid pack (the rectangular module bolted to the valve body), and measure each solenoid coil resistance — typical Chrysler spec is 10-30 ohms per solenoid; open or shorted readings confirm the solenoid pack is the failure.
  5. Smaller cases: a clogged solenoid screen filter from internal debris will also throw P1740.
  6. Don't condemn the entire transmission on a P1740 until you've ruled out the solenoid pack ($150-$300 part), the fluid (cheap), and the TCM connector — full rebuilds run $2,500-$4,500 and are wrong 40% of the time when the real fix was a $250 solenoid pack.
Vehicle-specific patterns2003-2010 Dodge Ram / Durango / Jeep Grand Cherokee with the 545RFE 5-speed automatic behind the 4.7L V8 or 5.7L Hemi is the textbook P1740 platform…
  • 2003-2010Dodge Ram / Durango / Jeep Grand Cherokee with the 545RFE 5-speed automatic behind the 4.7L V8 or 5.7L Hemi is the textbook P1740 platform — the solenoid pack fails between 100-150K miles and the symptom is harsh 2-3 shifts plus the code.
  • 1996-2007Chrysler/Dodge minivan and front-drive sedans with the 41TE / 42LE / A604 4-speed automatic (Caravan, Town & Country, Intrepid, 300M, Sebring) throws P1740 from solenoid pack failure as the #1 cause and from the well-known input/output speed sensor failures as the #2 cause.
  • 2000-2010Jeep Wrangler / Cherokee with the 42RLE behind the 4.0L throws P1740 from TCC solenoid failure or from a worn converter lockup clutch friction material — a fluid-and-filter service catches it early if the customer notices the highway shudder.
  • 2005-2014Chrysler 300 / Dodge Charger with the W5A580 (Mercedes-sourced 5-speed) throws P1740 less often but the diagnostic path is the same.

Estimated repair$250 (solenoid pack DIY + fluid on a 41TE) to $4,500 (full rebuild of a 545RFE at a transmission shop).

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