P0709: Transmission range sensor or switch signal that cuts in and out
Transmission range sensor circuit intermittent
Severity: Severity not verified — if the car runs badly, have it inspected
We found no source that rates P0709. TroubleCodes.net lists transmission shift symptoms for related circuits, so how it affects driving depends on the vehicle.
It gets more serious if:
- Inspect soon: If the transmission shifts harshly, will not engage, or the gear indicator is wrong, have it inspected soon.
P0709 in short
P0709 means the transmission range sensor, which tells the computer whether the selector is in park, reverse, neutral or drive, is sending a signal that drops out or glitches. Wiring, a poor connection or the sensor itself are the usual causes.
The transmission range sensor, also called the range switch or PRNDL input, reports the selector position to the computer. P0709 is the intermittent version of the range sensor fault: the signal is there at times and missing or wrong at others.
TroubleCodes.net lists wiring, poor connections, the sensor or switch, and the control module as the probable causes. Because the fault comes and goes, a loose or corroded connector is a sensible first look.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Wiring or a poor connection at the range sensor
Common general cause- Why it ranks here
- TroubleCodes.net lists wiring and poor connections first, which fits a signal that comes and goes.
- What would change this
- Rises if moving the harness or connector changes the range reading. Falls if the reading is steady and connections are tight.
Cause 2: Failing transmission range sensor or switch
Common general cause- Why it ranks here
- TroubleCodes.net lists the sensor or switch itself.
- What would change this
- Rises if the displayed gear position flickers with a good harness. Falls if the position reading is steady in every selector position.
Cause 3: Transmission or engine computer fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net lists the ECM, PCM or TCM, but it is the least likely cause.
- What would change this
- Rises only after wiring and the sensor test good. Falls if any wiring or sensor fault is found.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read the stored codes, then move the selector through each position while watching the gear position or range switch reading on a scan tool.
Warning:Do this with the parking brake set and the engine in park or neutral only. Keep the vehicle from rolling when you shift through the positions.
IfThe reading flickers or jumps while the selector is held still
It meansThe range signal is intermittent. Inspect the wiring and connector.
IfThe reading follows the selector cleanly
It meansThe fault is not present now. Check the connector for corrosion and watch for it to return.
Step 2: Inspect the range sensor connector and harness, then gently wiggle them while watching the range reading.
Warning:Keep hands clear of moving parts and the exhaust, and keep the vehicle secured with the parking brake. Transmission parts can be hot.
IfThe reading drops when the harness or connector moves
It meansRepair the wiring or connector.
IfNothing changes
It meansTest or replace the range sensor, then have a shop test the module.
Symptoms
- Check engine light on
- Gear indicator that flickers or shows the wrong position
- Harsh or delayed shifts, or the car will not start in park (unconfirmed) Gets more serious: stop and have it checked.
How to fix
Step 1: With the engine off, check that the range sensor connector is fully seated and the wiring is not rubbed or corroded.
Parts and cost context
- Transmission control module (TCM):Test the sensor, switch and wiring first. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
We don't have reviewed vehicle-specific evidence for P0709 yet. The causes and tests above apply across vehicles.
Related codes
P0709 questions
What does P0709 mean?
The transmission range sensor circuit is intermittent, meaning the signal drops out or glitches instead of being steady.
What is the difference between P0705 and P0709?
P0705 is the general range sensor circuit fault, while P0709 means the fault comes and goes.
Sources and review
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error