andygal 0 Posted April 17, 2008 Hey i have a 1994 corrado vr6. The idle on it is constantly high (about 2000rpm) I have scanned it with vagcom and get the following readings VAG-COM Version: Release 311.2-N Control Module Part Number: 021 906 258 AG Component and/or Version: MOTOR PMC 1 Software Coding: 0261203109 Work Shop Code: 1267357531 3 Faults Found: 00522 - Engine Coolant Temperature Sensor (G62) 30-00 - Open or Short to B+ 00527 - Intake Manifold Temperature Sensor (G72) 30-00 - Open or Short to B+ 00513 - Engine Speed Sensor (G28) 03-00 - No Signal I have replaced the ISV and its still the same. new coolant temp sensor as well and it reads about 28ohms???? when warm. The wiring for the plug has been tested back to the ecu and that is fine...no breaks there. When i plug a 2nd isv in (off the car) with the car warm, the valve opens about a quarter!! Have unplugged the ecu and disconected the battery then done the ecu reset but still the same!! Anyone got any ideas as im confused Cheers, Andy Quote Share this post Link to post Share on other sites
mattkh 0 Posted April 17, 2008 Hi Put up a picture of the engine, a birds eye view. Quote Share this post Link to post Share on other sites
andygal 0 Posted April 17, 2008 ok confused but here you go lol Cheers, Andy Quote Share this post Link to post Share on other sites
Toad 0 Posted April 17, 2008 The inlet temp sensor and engine speed sensor aren't plugged in the wrong way round are they? Quote Share this post Link to post Share on other sites
Toad 0 Posted April 17, 2008 O/T The expansion tank cap could do with swapping for a blue one. Quote Share this post Link to post Share on other sites
andygal 0 Posted April 17, 2008 no idea toad...where are they located and il check??? Also why change the exp tank cap?? Cheers, Andy Quote Share this post Link to post Share on other sites
mattkh 0 Posted April 18, 2008 Hi Thanks for the photo. In some cases the black cap led to overheating. The blue one cured it. I would clean the maf sensor with a gentle carb cleaner or maplins switch cleaner. Check the vacuum pipes and consider whipping out the ISV and cleaning it out with carb cleaner/petrol. Quote Share this post Link to post Share on other sites
andygal 0 Posted April 18, 2008 tried all the above. when i clear the codes, the revs drop for a second then they come back and the shoot up!!!! thinking it must have something to do with the temp sensor but as the wire seems to be ok back to the ecu and the sensor is reading a resistance, i dont no what it could be?? Cheers, Andy Quote Share this post Link to post Share on other sites
Toad 0 Posted April 19, 2008 no idea toad...where are they located and il check??? Also why change the exp tank cap?? Cheers, Andy The inlet air temp sensor is the plug going into the inlet manifold by the fpr and the wires should be taped into the loom with the yellow and blue temp sensors. then the other temp sensor is located next to the yellow and blue sensors in the thermostat housing, and the wiring should connect to the loom that runs to the starter motor. It's easy to get them all mixed up.. The temp sensors can also get mixed up. the black connection always goes to the black sensor, but the others can change colour I think. Quote Share this post Link to post Share on other sites
dirtytorque 0 Posted April 19, 2008 could be a vac leak.. Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 ok checked and all hoses are ok as are all plugs. scanned again with vagcom today and following codes VAG-COM Version: Release 311.2-N Control Module Part Number: 021 906 258 AG Component and/or Version: MOTOR PMC 1 Software Coding: 0261203109 Work Shop Code: 1267357531 4 Faults Found: 00527 - Intake Manifold Temperature Sensor (G72) 30-00 - Open or Short to B+ 00522 - Engine Coolant Temperature Sensor (G62) 30-00 - Open or Short to B+ 00518 - Throttle Position Sensor (G69) 30-10 - Open or Short to B+ - Intermittent 00513 - Engine Speed Sensor (G28) 03-00 - No Signal Throttle position sensor is a new one?? Cleared them and the only 2 that came back were the temp sensors. They came back straight away, cleared them while runnig, the revs dipped down then back up when the faults came back a split second later. Anyone???? Pretty sure the wirings ok. Cheers, Andy Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 checked the resistance between the + terminal on the plug for the temp sensor and the battery and its 2.7kohms. Looks like a short somewhere?? Checked the resistance again between where the plug goes into the ecu and the battery and no continuatity. Soooo....the circuit must be shorting in the ecu???? Andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted April 19, 2008 Have you checked continuity between the sensor plug ang and ECU plug... I think both these sensors earth thru the ECU so that might be the issue... Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 yupp no continuity between sensor plug and ecu plug. earths through the ecu?? what this mean then?? Both the terminals on the plug have continuity with earth?? Cheers, Andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted April 19, 2008 Pin 33 I think mate - sensor earth - not sure where that goes from the ECU - probably the relay? have you changed this?? Pin 2 on both the IAT and CTS earth back to ECU pin 33 along with the TPS which is interesting - did the other 2 faults come up before you changed the throttle sensor or only afterwards??? Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 hey iv not changed the throtle sensor!! Ye the two temp sensors earth through the ecu...cant remember the bin but its the green and black??? wire. This seems to be fine. Its the other wire..blue in colour which goes back to the ecu which is also reading continuity to earth!! Cheers, Andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted April 19, 2008 Throttle position sensor is a new one?? - sorry thats what confused me, I thought you meant you'd changed it... Ok - So you have looked for continuity from PIN2 or the sensor plug(s) to PIN 33 on the ECU plug? What about Pin 33 on the ECU back to the battery Negative? I would at least re-seat the ECU relay or change for a new / known working one and maybe also look for corrosion on the big multi-plug in the engine bay Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 sorry bout that. you checked Pin 33 etc. ECU plug to battery....no continuity. Where is the ECU relay then? under at the fuse box i take it?? any idea what one?? Also wheres the best place too get one and how much roughly (dealers??) The ECU plug and twist connector in the engine bay are both ok and free from corrosion!!!! Arghhh i hate car electrics!! Cheers for the help btw!! Andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted April 19, 2008 No worries - ECU relay should be the 3rd one in the top row I think (above the fuse box) - maybe grey in colour (most are black) - maybe numbered 30/31//32 (without checking) Quote Share this post Link to post Share on other sites
andygal 0 Posted April 19, 2008 ok cheers il check this is seated ok tomorrow and probs get a new one monday to eliminate it. Any way of checking these...no?? If this is ok any other ideas about what i can check lol?? Cheers, Andy Quote Share this post Link to post Share on other sites
CazzaVR 0 Posted April 19, 2008 Think the ecu relay is 109- changed mine and the fuel pump relay a couple of months ago. Quote Share this post Link to post Share on other sites
andygal 0 Posted April 21, 2008 sorteeeed. ended up being a dry joint in the ecu. soldered it up and all is good :) Cheers for the help guys Andy Quote Share this post Link to post Share on other sites
Supercharged 2 Posted April 21, 2008 Nice one mate!! good bit of troubleshooting there! Quote Share this post Link to post Share on other sites
