AH10 2.4 gear shift prob. Not reaching 4th. Also p0793 code

[DaveAn]

Hi Folks, greeting from Northern Ireland. I'm the happy owner of Bertha,  a late 2007 facelifted AH10 that I bought in Glasgow and ferried home. Over the past month, I have noticed that about five miles into my journey, the engine warning light comes on (P0793) and she won't get into top gear (4th). At some point prior to this there is a fairly clunky gearshift - only the one -  which seems to be part of the picture.

 

This is not affecting me massively during the week as I'm in rush-hour traffic during a 10 mile commute so my need for 4th gear is limited. But at the weekends when we like to stretch our legs a little, it's a pain to do 60+ miles in 3rd gear.

 

I have seen 2 similar threads by Sorocco (March 2023) and Lucho (Jan 2025) and have reached out to them.

 

1. Has anyone any insight into this?
2. Can I do the work myself? Specialists who deal with Auto-boxes are (a) as rare as hens teeth and (b) not within 60 miles of me. I'm technically still a chartered engineer even though I haven't got down and dirty in many years.

 

VIN is ANH10-0195197.

[Soroco]

30 minutes ago, DaveAn said:

Hi Folks, greeting from Northern Ireland. I'm the happy owner of Bertha,  a late 2007 facelifted AH10 that I bought in Glasgow and ferried home. Over the past month, I have noticed that about five miles into my journey, the engine warning light comes on (P0793) and she won't get into top gear (4th). At some point prior to this there is a fairly clunky gearshift - only the one -  which seems to be part of the picture.

 

This is not affecting me massively during the week as I'm in rush-hour traffic during a 10 mile commute so my need for 4th gear is limited. But at the weekends when we like to stretch our legs a little, it's a pain to do 60+ miles in 3rd gear.

 

I have seen 2 similar threads by Sorocco (March 2023) and Lucho (Jan 2025) and have reached out to them.

 

1. Has anyone any insight into this?
2. Can I do the work myself? Specialists who deal with Auto-boxes are (a) as rare as hens teeth and (b) not within 60 miles of me. I'm technically still a chartered engineer even though I haven't got down and dirty in many years.

 

VIN is ANH10-0195197.

Hi Dan mine was a broken wire ion the connector. 

[Rojie]

35 minutes ago, DaveAn said:

Hi Folks, greeting from Northern Ireland. I'm the happy owner of Bertha,  a late 2007 facelifted AH10 that I bought in Glasgow and ferried home. Over the past month, I have noticed that about five miles into my journey, the engine warning light comes on (P0793) and she won't get into top gear (4th). At some point prior to this there is a fairly clunky gearshift - only the one -  which seems to be part of the picture.

 

This is not affecting me massively during the week as I'm in rush-hour traffic during a 10 mile commute so my need for 4th gear is limited. But at the weekends when we like to stretch our legs a little, it's a pain to do 60+ miles in 3rd gear.

 

I have seen 2 similar threads by Sorocco (March 2023) and Lucho (Jan 2025) and have reached out to them.

 

1. Has anyone any insight into this?
2. Can I do the work myself? Specialists who deal with Auto-boxes are (a) as rare as hens teeth and (b) not within 60 miles of me. I'm technically still a chartered engineer even though I haven't got down and dirty in many years.

 

VIN is ANH10-0195197.

 

Hello David, 

 

Welcome to the Forum.

[dezufo]

In case you have not researched the fault code: DTC P0793, found in many Toyota vehicles, indicates a problem with the Intermediate Shaft Speed Sensor A circuit. This sensor measures the rotational speed of the intermediate shaft in the transmission and sends this data to the transmission control module (TCM) to help with gear selection. A P0793 code means the sensor is either not sending a signal, or the signal it's sending is not being recognized by the TCM.  

Symptoms:

You might experience a check engine light, transmission issues (e.g., rough shifting, difficulty engaging gears), or increased fuel consumption. 

Importance:

The intermediate shaft speed sensor plays a crucial role in controlling the transmission, and a faulty signal can lead to transmission damage or improper performance. 

 

If it was mine I would not be driving long distances.

 

 

[DaveAn]

@defuzo Thanks and you may well have guessed that I have googled this to death. Yes, this is the intermediate speed sensor. The intermittentness of the fault confuses me  but it clunks in, regular as clockwork at around the 3 or 4 mile part. If I knew where the sensor was located I would happily replace it but the YouTube videos I have seen are foreign language (to me) and out of focus. I think I may have located the 2 sensors in the attached pics - with a long reach and possibly removing the battery (probably a good idea anyway) I can probably reach down with a socket extension but I would appreciate further guidance and a yay/neh before I dig out the socket set. I think the part number is 8941324010 (Picasso's recommendation to Sorocco) which I can source via ebay here easily enough.

 

Any other thoughts?