11 replies to this topic

[andywilson]

Afternoon ladies and gents! As you may have read in a recent wanted ad, I've just got back from a trip to the Swiss alps. Unfortunately my Elise only made it to Belgium! After stopping for fuel I had a variety of fault codes and the car wouldn't come out of limp mode no matter what I tried. Even when I tried to drive it, after 3 minutes it would die altogether. Unfortunately it was late and I had no support in a French speaking country so after a few hours checking the obvious I threw in the towel and she's getting taken home. So these are my fault codes: N/A (?!) P0123 P0638 P2104 P2106 P2100 P0233 P0123 P0638 P2104 (again?!) P0101 It's a Toyota engined non supercharged Elise, with an aftermarket full exhaust system, inc cat (don't know any more than that), lightened flywheel and a K&N panel filter. My gut feeling is the MAF sensor as it's an oiled panel filter, but thought I'd open it up to you lot. There are a couple of posts on sell that suggest a new throttle body is the answer? It's always had an issue where maybe once a month when hot starting this would happen but after turning on and off again it always cleared itself. It had never got any worse so I just lived with it. When it's in limp mode, the revs hunt between 1000/2500 and any throttle input makes the engine almost stall. Any ideas guys? Much appreciated! Andy

[jonnyboy]

Throttle body would be a start ours a very common fault. The corolla one is compatible and far cheaper to source from the US I'm assuming its the 134? You get the same issue on the 190 in fact it happens on almost all cable throttle ones. The 190 TBs are more expensive.

[hairy]

Have you tried SELOC Andy?

[andywilson]

I've tried a throttle body off eBay about 6 months ago, however as the fault was so infrequent it was hard to tell if it improved things. However the fault reoccurred with both new and old TBs I did get a price from Toyota for a new one and it was in the region of £1100! Maybe another second hander is worth a try? Or a US one as per your suggestion. I did try seloc a while back,, however the technical knowledge doesn't seem to compare to here!

[hairy]

Even Arno?

[fezzasus]

My gut feeling is the MAF sensor as it's an oiled panel filter, but thought I'd open it up to you lot.

 

Feels like it to me

Edited by fezzasus, 09 July 2017 - 06:25 PM.

[Nev]

If you disconnect the MAF most ECU's will run in open loop mode, which might improve things massively. Give it a try as it's so easy to do.

 

 

[Arno]

Having duplicate codes usually means they happened more than once and are stored or your OBD reader is heaping historic or snapshotted codes together with active ones.

 

Some of the P210x ones are just feedback codes from the ECU meaning it has forced the engine into a failsafe 'idle' mode.

 

P2100 is one that's interesting. ECU complains that the circuit driving the motor in the electronic throttle body has gone open circuit. Could be a bad TB (electric motor died) or a wiring issue. This likely caused the ECU to set the P210x.

 

P0123 is a generic 'TPS high' warning. Which may also point to a wiring issue. Perhaps a grounding issue in the TB or wiring is causing the electric motor to try to ground through other circuits.

 

You do have a MAF error (P0101) mening it's readings are out of range to what the ECU is expecting.

 

Main issue seems to point to the control and feedback of the TB itself at the moment. No errors about the pedal side of things.

 

May sound odd, but if it's really 'broken' now it may make finding the root cause easier. Just make sure to only work on 1 thing at a time and try not to disturb anything else. Hopefully you can work through the different areas to pinoint the problem area that makes it work or breaks it all of the time.

 

MAF would be a secondary issue and indeed oil from a filter may have contaminated it. There's special MAF cleaning fluid (a bit like brake cleaner, but less agressive) on the market. Needs very gentle cleaning though! Very easy to damage the small resistor wires.

 

Bye, Arno.

[siztenboots]

grounding issue?

[andywilson]

Thanks very much for the help so far.

 

When it arrives back Europe next week I'll make a start and report back my findings.

 

Thanks again,

Andy

[andywilson]

Update... I got the car back on Wednesday and replaced the maf for a known good Toyota part and took out the K&N filter and fitted a Toyota paper filter. I since cleared the codes and have tried three different throttle bodies, all of which throw up the same codes: P2104 P0638 As per a couple of weeks ago the revs are at about 1800 and very little throttle response. I'm not sure what to check next, it's possible I've been supplied another bad TB I guess. It was an eBay item. What about the pedal end, are these common problems? Thanks, Andy

[Arno]

As you have tried different TB's and these codes still come out:   P0638 = Throttle Actuator Control Range/Performance   Means the ECU can't control the electric motor in the TB correctly It's trying to move the butterfly a certain amount and it's feedback is not matching with the 'commanded' value. The dual feedback system seems to be OK as it's not throwing a code that one is 'off' from the other, so likely it can be trusted.   P2104 = Throttle Actuator Control System Forced Idle Which just means that becasue of P0638 the ECU has forced the system to (close to) idle and in failsafe mode. A kind of follow-on code from the earlier one. The issue is between the ECU motor driver output and the TB electric motor. Likely you'll need to check the condition of the pins/contacts in the plug that connects the engine loom to the TB, the wiring loom parts (eg. wire breaks near/at the connector or rubbing/breakage) and also check continuity between the wiring loom connector on the ECU and the TB connector.

 

It may end up being a damaged/dead ECU that has a fried TB output stage, but contact/wiring issues are more likely.

 

None of the codes point to the pedal side of the system. Both codes are related to the ECU/TB interaction itself.

 

Bye, Arno.