Code P0731, check engine light came on?

Tiny
PHILGLENN48
  • MEMBER
  • 2018 DODGE JOURNEY
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 65,000 MILES
The car just started acting up after we've had monsoon rain here in Oklahoma been parked the whole time out of the rain check engine light came on and will not shift out of 1st not even using the manual slap stick. Can someone please help me? I've never had a problem with this car until now. Had it a year got it used.
Friday, May 2nd, 2025 AT 6:06 PM

21 Replies

Tiny
KEN L
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So this code comes up when the transmission fluid is low or needs service, also the input shaft speed sensor can be bad as well.

P0731 - Gear 1 Incorrect Ratio

I would start by checking the fluid level, here is a guide to help you and instructions below for your car:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

Next, I would swap out the input shaft sensor with a new part. The transmission may have an internal problem, but we should do the easy stuff first. Check out the images (below). Let us know how it goes.

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Saturday, May 3rd, 2025 AT 12:40 PM
Tiny
PHILGLENN48
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Input shaft speed sensor is this expensive, I checked the transmission fluid it registers on dip stick so I'm guessing it's a bad sensor is this typical for 65,000?
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Saturday, May 3rd, 2025 AT 1:44 PM
Tiny
KEN L
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Yes, sensors can go bad at any time, the input shaft sensor is the first thing to be replaced when getting the P0731 code.
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Sunday, May 4th, 2025 AT 11:07 AM
Tiny
PHILGLENN48
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How much do you think the sensor would be mean might try to get a loan.
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Sunday, May 4th, 2025 AT 11:40 AM
Tiny
PHILGLENN48
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Thank you. Once I get the money for the fluid and part, I'll let you know if it fixed the problem.
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Monday, May 5th, 2025 AT 10:40 AM
Tiny
KEN L
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Sounds good.
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Monday, May 5th, 2025 AT 11:13 AM
Tiny
PHILGLENN48
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How are you doing Ken? I put the transmission fluid in there but it's still slipping gears and not shifting. Do I need to take the computer scanner and erase the engine code in order for it to work right or would it still be the bad sensor?
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Friday, May 9th, 2025 AT 2:25 PM
Tiny
PHILGLENN48
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Took obd2 scanner and erased code still doing it probably the input sensor.
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Friday, May 9th, 2025 AT 6:29 PM
Tiny
KEN L
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I would try the input sensor, and if that does not work there is a machinal failure inside the transmission.
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Saturday, May 10th, 2025 AT 11:52 AM
Tiny
PHILGLENN48
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Hi Ken, okay, if I'm sitting in the driver seat looking out of the windshield what side would the sensor be on? I only ask this because I've never worked on a transmission for four cylinder the engine sits in the up under the hood sideways but I'm not sure how the transmission itself sits under the car that's why I'm asking and when I locate this input shaft sensor when I go to replace it will any transmission fluid come out so should I have some oil Rags with me or when I take it out will nothing come out I don't know because I've never worked on one I'm just asking.
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Saturday, May 10th, 2025 AT 12:32 PM
Tiny
KEN L
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If you check out the image above it shows the sensor on the left side of the transmission, so that would be near the radiator. Transmission fluid will no spill out so no worries there. If you have troubles let me know so I can help walk you through the repair.
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Sunday, May 11th, 2025 AT 11:26 AM
Tiny
PHILGLENN48
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Hi Ken it's Philip, still having the issue to come to find out cruise control still works do you still think it's the input sensor.
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Wednesday, May 21st, 2025 AT 1:35 AM
Tiny
PHILGLENN48
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Hi, crawled up under the journey and saw a sensor on there behind all the air duct on side of transmission between engine and radiator hoping I found the right one wondering if I found the right one, and please don't tell me when starter goes out the transmission has to be dropped if I think that the case looks like it's inside trans housing.
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Wednesday, May 21st, 2025 AT 8:36 AM
Tiny
KEN L
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The sensor is outside the housing, please recheck the images above.
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Thursday, May 22nd, 2025 AT 10:09 AM
Tiny
PHILGLENN48
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Well Ken, phone just got turned on I've tried and I can't get to it any suggestions the one sensor I can't even hardly see was barely able to put tip of finger on it that's a lot of work do you know anyone in okc area that could do it for a reasonable price.
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Monday, June 16th, 2025 AT 8:45 PM
Tiny
KEN L
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I would call around to different garages and get an estimate. I am sorry you are having these issues.
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Tuesday, June 17th, 2025 AT 6:49 AM
Tiny
PHILGLENN48
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Hi Ken, I called around to a couple of mechanic shops I told them what year the make and model of this car I got and they told me I might as well just take it across the scale let the company repossess it it's beyond getting fixed he asked me how much I owe I said 13 to 14,000 and he says the transmission is dying all the other gears are dead that's why it won't shift out of first and he told me a new transmission or used transmission shop cost and everything is going to be 5 to 7,000. I'm broke so I'm going to take his word for it I'm going to take the tag off the car let this company repossess it I'm not going to make any more payments on it and if need be I'll get it Uber go to a bus station and I'm getting out of state I'm going to go to Florida Palm Coast or Fort Pierce and I'm going to start a new life all I've ever had are lemons for vehicles I just need to change a of pace be able to walk on the beach be able to drink a beer get a head buzz and just some beautiful beaches crashing waves sunrise sunset drink some beers get drunk I'll live with a friend out there in Florida and just try to get a job get reestablished and enjoy the rest of my life.
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Wednesday, June 18th, 2025 AT 5:50 PM
Tiny
KEN L
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Yep, sometimes it is best to have a new adventure :)
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Wednesday, June 18th, 2025 AT 6:02 PM
Tiny
PHILGLENN48
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Ken, you seem pretty down to earth I will stay in touch with you handshakes to you and Pat on back thank you a bunch for trying to help with this car.
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Thursday, June 19th, 2025 AT 10:51 AM

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