Location of throttle position sensor 2.6 V6

[Steve B]

Thanks..I think! 

My problem is that the car has an issue (and has had one intermittently) with the autobox. If I have keep the throttle pressed lightly (say, in medium traffic) and then accelerate quite lightly the revs will rise sharply and the autobox will not change up ...then it does with a donkey-kick and the limp-home light comes on. If I turn everything off and wait 30seconds, the engine is re-set normally. In contrast, if I start from nothing and accelerate hard, the autobox will change up no problem.

It COULD be the autobox or its ECU but, it COULD be one of the throttle sensors. I bought an aftermarket one (like the old ones on the 2.5), but can't figure out where it goes. I can see the throttle body on the car with a sliver clip on top. If I remove that, will I see the standard 3-pin sensor behind it?

Did you look for codes 

http://www.omegaowners.com/forum/index.php?topic=90581.0

[Migalot]

Thanks..I think! 

My problem is that the car has an issue (and has had one intermittently) with the autobox. If I have keep the throttle pressed lightly (say, in medium traffic) and then accelerate quite lightly the revs will rise sharply and the autobox will not change up ...then it does with a donkey-kick and the limp-home light comes on. If I turn everything off and wait 30seconds, the engine is re-set normally. In contrast, if I start from nothing and accelerate hard, the autobox will change up no problem.

It COULD be the autobox or its ECU but, it COULD be one of the throttle sensors. I bought an aftermarket one (like the old ones on the 2.5), but can't figure out where it goes. I can see the throttle body on the car with a sliver clip on top. If I remove that, will I see the standard 3-pin sensor behind it?

Did you look for codes 

http://www.omegaowners.com/forum/index.php?topic=90581.0

Not yet. Haven't had any spare time. 

I may have a moment tomorrow. Will report back!

[Migalot]

Carried out the pedal trick and got 0500 & 1700:


P0500 Vehicle speed sensor malfunctionB-009

P1700 Service Vehicle Soon Request from Transmission Control Module

What do I do now? Help! 

[Migalot]

Can anyone let me know the part number for the automatic gearbox speed sensor for my 2002 2.6 V6?

Easy to fit? 

[Kevin Wood]

The codes you have a re from the engine ECU. They indicate a problem in the automatic gearbox ECU, but you can't read that with a pedal trick. I would get the car to someone with a Tech 2 or something that can read gearbox codes.

The engine ECU's Vehicle Speed Sensor input comes from the ABS ECU via the CAN bus, for example, so this doesn't point to a specific sensor failure. Find out what the gearbox ECU is complaining about and you'll know more.

[Migalot]

The codes you have a re from the engine ECU. They indicate a problem in the automatic gearbox ECU, but you can't read that with a pedal trick. I would get the car to someone with a Tech 2 or something that can read gearbox codes.

The engine ECU's Vehicle Speed Sensor input comes from the ABS ECU via the CAN bus, for example, so this doesn't point to a specific sensor failure. Find out what the gearbox ECU is complaining about and you'll know more.

Yes, but a speed sensor fault would be a likely candidate, wouldn't it? I don't know of anyone local with a Tech2 and it would cost a shed-load to get a Vx agent to read the codes.

If I can locate a speed sensor for less than £50, I'm prepared to take a punt on that being at fault.

[Kevin Wood]

No, I wouldn't say it's likely to be a speed sensor fault. The engine ECU is complaining that the gearbox ECU has raised a fault. Without reading the gearbox ECU we don't know why that is.

The engine ECU is also complaining about a speed sensor issue. The engine ECU doesn't have a speed sensor, since it gets that information via the CAN bus from the ABS ECU, which has a speed sensor on each wheel.

I would put money on that being a spurious error that has arisen because the gearbox ECU is upset and that also communicates on the same CAN bus.

The symptoms seem to be that the gearbox is misbehaving, so I'd bet on the gearbox ECU having other fault codes raised, which will tell us what the problem is.

Purchasing anything at this stage will be a waste of money. If I were going to spend anything I'd get a local garage to read the gearbox ECU fault codes.

[Migalot]

No, I wouldn't say it's likely to be a speed sensor fault. The engine ECU is complaining that the gearbox ECU has raised a fault. Without reading the gearbox ECU we don't know why that is.

The engine ECU is also complaining about a speed sensor issue. The engine ECU doesn't have a speed sensor, since it gets that information via the CAN bus from the ABS ECU, which has a speed sensor on each wheel.

I would put money on that being a spurious error that has arisen because the gearbox ECU is upset and that also communicates on the same CAN bus.

The symptoms seem to be that the gearbox is misbehaving, so I'd bet on the gearbox ECU having other fault codes raised, which will tell us what the problem is.

Purchasing anything at this stage will be a waste of money. If I were going to spend anything I'd get a local garage to read the gearbox ECU fault codes.

OK, Kevin.

I've found someone local to get the codes read for £35, so I may pop there on Thursday. I'll report back. 

[Migalot]

Had he codes read and it looks like the gearbox is fubared. 

P0730 Incorrect Gear Ratio
P1625-002 Controller voltage switch signal too low   

The car still runs OK as the fault is intermittent, but I am now actively looking to see how I can finance a new set of wheels.

Shame, really — especially as it has only done 59k from new. 

[Kevin Wood]

That looks like an electrical issue with the pressure control solenoid. If you're lucky and it hasn't slipped too much while driving, you might find the gearbox is OK.

First thing to do is to check the large round connectors behind the battery are all seated properly. Have a look at the wiring down to the automatic gearbox too, especially into the connector to the front casing of the gearbox. Look for any damage to the wiring or loose connectors. Failing that, drop the front sump on the gearbox and check the wiring inside the box.

The solenoid appears between pin 52 and 5 of the gearbox ECU and, if you pull off the connector and measure resistance here into the wiring loom, you should see 3.5-6.0 Ohms.

[Steve B]

Had he codes read and it looks like the gearbox is fubared. 

P0730 Incorrect Gear Ratio
P1625-002 Controller voltage switch signal too low   

The car still runs OK as the fault is intermittent, but I am now actively looking to see how I can finance a new set of wheels.

Shame, really — especially as it has only done 59k from new. 

I had that code on the AR25 it was put down to the 2-3 solenoid in the box

Your symptons are the same as this member too

http://www.omegaowners.com/forum/index.php?topic=135356.msg1738682#msg1738682

[Migalot]

That looks like an electrical issue with the pressure control solenoid. If you're lucky and it hasn't slipped too much while driving, you might find the gearbox is OK.

First thing to do is to check the large round connectors behind the battery are all seated properly. Have a look at the wiring down to the automatic gearbox too, especially into the connector to the front casing of the gearbox. Look for any damage to the wiring or loose connectors. Failing that, drop the front sump on the gearbox and check the wiring inside the box.

The solenoid appears between pin 52 and 5 of the gearbox ECU and, if you pull off the connector and measure resistance here into the wiring loom, you should see 3.5-6.0 Ohms.

Thanks, Kevin. I'll check the battery connectors. 

The fault first appeared about four years ago and would come back intermittently with intervals of up to three/six months. It's only recently that it has been happening a bit more often. That said, on the way back from the garage today, the box behaved normally.