Timing belt that has jumped one or more teeth due to wear or improper tension; Failed timing belt tensioner or idler pulley allowing belt slack; Worn or damaged timing belt teeth that skip on the sprockets; Incorrect timing belt installation after a recent repair; Camshaft or crankshaft position sensor signal interference or faulty sensor; Wiring damage or corrosion in the camshaft or crankshaft sensor circuits; Mechanical wear in the timing components such as a worn sprocket or keyway

DTC codes / Chrysler codes / P1390

P1390 · ChryslerTiming Belt Skipped One Tooth Or More

Q: What does code P1390 mean?

Timing Belt Skipped One Tooth Or More. P1390 on Chrysler vehicles indicates that the powertrain control module has detected a mismatch between the crankshaft position sensor and camshaft position sensor signals that is consistent with the timing belt jumping one or more teeth. The computer compares these two signals continuously and sets this code when the mechanical timing relationship falls outside the expected window.

P1390 on Chrysler vehicles indicates that the powertrain control module has detected a mismatch between the crankshaft position sensor and camshaft position sensor signals that is consistent with the timing belt jumping one or more teeth. The computer compares these two signals continuously and sets this code when the mechanical timing relationship falls outside the expected window.

SystemPowertrain

Code typeChrysler specific

SeverityHigh

Fix difficultyProfessional

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire that may feel like a shaking engine
Loss of power or sluggish acceleration, especially under load
Hard starting or extended cranking before the engine fires
Poor fuel economy or increased emissions
In severe cases, the engine may stall or fail to start

Common causes, most likely first

Timing belt that has jumped one or more teeth due to wear or improper tension
Failed timing belt tensioner or idler pulley allowing belt slack
Worn or damaged timing belt teeth that skip on the sprockets
Incorrect timing belt installation after a recent repair
Camshaft or crankshaft position sensor signal interference or faulty sensor
Wiring damage or corrosion in the camshaft or crankshaft sensor circuits
Mechanical wear in the timing components such as a worn sprocket or keyway

How to diagnose and fix it

Verify the fault with a scan tool by checking live data for cam and crank synchronization and reviewing freeze-frame data
Inspect the timing belt, tensioner, and idler pulleys for wear, slack, or missing teeth
Perform a mechanical timing check by aligning the crankshaft and camshaft timing marks to confirm belt position
Test the camshaft and crankshaft position sensors and their wiring for continuity and signal integrity
If the belt has skipped, replace the timing belt, tensioner, and any worn pulleys as a set
Clear the code and road test the vehicle to confirm the repair and ensure the code does not return
If the code persists after mechanical repair, recheck sensor signals and the PCM for proper operation

Timing belt codes that fool good technicians

A stretched or worn timing belt can cause this code without visibly missing teeth, so always measure belt deflection and inspect the tensioner.
Camshaft or crankshaft sensor faults can mimic a skipped tooth, so verify sensor signals with an oscilloscope before condemning the belt.
After replacing the timing belt, the code may remain stored until the PCM completes a drive cycle, so clear it and perform a full relearn procedure.
On some Chrysler engines, a weak battery or poor ground can cause intermittent sensor signals that set P1390 without any mechanical timing issue.
A jumped timing belt often causes no driveability symptoms at first, but continued driving can lead to valve and piston damage if the belt slips further.

Can I keep driving with P1390?

Do not continue driving with this code if the engine is running rough or misfiring, as a slipped timing belt can cause catastrophic engine damage. If the only symptom is the warning light, drive directly to a repair shop at low speed and avoid heavy acceleration.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.