DJGLW

Are you certain it's getting fuel? What is the history around the time of the fault? Have you read the fault codes and have you checked there is +12v at the relay? Lastly where are you?

Thanks Steve. There are tons of vids on YT on Audi's but mainly B6/B7. Any clues on which one? The cable is so tight on the ECU in that box that I'm not keen on removing the box. Is the box bolted in? The scuttle cover is already off to access the box. Is it a sensor or is it a switch on the master cylinder and does it feed to another relay? If yes what relay as it would let me check the switch/sensor before ripping the box out. Btw I'm certain when I stripped the Ign switch I was able to meter out the transducer coil and get a reading in ohms though I never noted it. Pic 1 shows transducer loop in partially stripped ign switch and the two pins to test its continuity. Pic 2 show ign switch part number which is 8KO 909 131 C. I mention this as the C is critical. The replacement I got didn't have the C and wouldn't fit. The difference is circled in red in pic 3 and stops it sliding into the dash frame. Is the ECU in the scuttle box the main engine start ecu? If it is would I be able to check the clutch switch through the harness connector if I knew the pinout? Thanks for all your patience. I suspect this thread will be use to others going forward.

Again thanks Steve. The beauty of what I've unravelled is the non crank problem seemed to be a fairly common fault with Audi's. From what I read getting at the starter to check it is a right pain and several hours under the car. My way checks not only the starter but also the solenoid effortlessly. Don't even get dirty hands and definitely proves whether the fault lies there or not. So there is the key switch which tonight is again flashing up as faulty intermittently, the clutch switch, the ECU and the thing on the battery lead in the boot. I dismantled my key switch and all 4 microswitches are operating correctly. I really would like to find the pins and how to check the transducer which I assume could be tested with with my ohmmeter before I buy another one? Then it's got to be the clutch switch. Interestingly my cruise stopped working a while back but my understanding is they are switched separately on the clutch pedal although I cannot see either switch. I wonder how many of these have been scrapped because of the no crank issue?

So I've solved two problems. I can get the car to start but more important I have a method for checking the starter and solenoid in under 20 seconds. I'm sharing it here but stressing this only applies to my car and variant and you should NOT use this if you don't understand how it works and if you do try it, you do so at your own risk & peril. Have the car in neutral gear and the handbrake firmly on. By measuring with a meter I identified which of the four 404 type relays operated the solenoid. See Pic 1 I then attached a very light gauge wire to the relay leg which fed power to the solenoid. See pic 2. The other end of the wire I simply touched to the +ve jumper peg under the bonnet as my battery is in the boot and with the ignition on it starts. See video. BE AWARE IF YOU DO THIS WITH THE CAR IN GEAR, IT WILL START AND DRIVE OFF, WITH THE CAR LIKELY TO KILL OR INJURE YOU THEN GO ON TO COLLIDE WITH SOMETHING OR SOMEONE ELSE. IMG_4032.MOV

I had the no crank problem due I thought to a low battery. Charged it overnight still no crank so I checked the fuses at both dash ends. It then started once. The next time I tried it a few hours later it wouldn't start and the battery was <10v. So as I had no other vehicle to go collect a battery, I had Halfords come and fit a new battery. I wrote telling them the battery had to have a BEM number and they would have to recode it to the car. They sent a battery but their fitter wouldn't code it saying it wasn't necessary. When it still wouldn't start he couldn't get out of here fast enough. I have since tried another key switch to no avail. Do you know where I could get the switch pinouts to try and test it tho it would be difficult given the plug/socket type. If I can get a proper wiring diagram I can test out all the components but I can't find anything. Typical VW. Hoard info whilst their dealers aren't interested unless it's a current model. Pity the law doesn't force them to publish all the info they have once their products, our cars, reach say 10 years of age.

Again thanks Steve. Yes the immobiliser is a possibility but would all the ign lights come on? Is there a way of disarming the immobiliser? Am using a generic OBDII code reader. I have cleared all the fault codes several times but these keeps coming up. I must say the lack of info on the net about UK Audi's is disappointing. The non-cranking issues appears very common especially in the USA. My problem is establishing which relay feeds the solenoid. I really want to put a live feed down the relay to the solenoid to test both the solenoid and starter but am finding too much conflicting info on which relay is the correct one?

A4 B8 Quattro Avante 6Sp UK RHD '09 Can anyone please confirm the 404 relay circled in yellow is the one which activates power to the starter solenoid? If it does then I can feed power straight to the solenoid to test the starter as it should take the ign switch, ecu and clutch pedal etc out the equation. Thanks

Thanks Steve. Would the failure to code prevent it turning over? My understanding was it would affect the charging but not prevent it cranking? I'm an idiot and completely forgot to include the DTCs my scan threw up. Do these throw any more light on matters? OBD-IIOBD-II DTCs: 1 ---------------------------- P2015 [0x2015] Intake manifold air control actuator position sensor/switch, bank 1 - range/performance problem Status: Pending ============================ 19. CAN Gateway19. CAN Gateway DTCs: 1 ---------------------------- 1771 [0x06EB] Headlight range control unit-J431 Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request ============================ 09. Onboard supply control unit No DTC found. ============================ 03. ABS control unit No DTC found. ============================ 01. Engine control unit01. Engine control unit DTCs: 2 ---------------------------- 4377 [0x001119] U101000: Electrical Parking Brake Control Module, Read out DTC Status bits: 1 Priority: 6 Frequency: 1 Unlearning index: 255 Odometer: 332486 km Date, time: 2008.05.27 01:25:21 Engine RPM: 0 rpm Calculated engine load value: 0.00 % Vehicle speed: 0 km/h Engine coolant temperature: 7 ℃ Engine oil temperature: 9 ℃ Distance traveled with MIL on: 99 kPa Klemme 30 voltage: 11 Paramteric values: 20 96 28 13 3B 00 00 11 88 00 00 13 3A 0B 00 10 5E 02 55 10 60 00 11 A6 08 98 12 FB 0B 48 Status: Test failed, Test failed (current drive cycle), Pending, Test failed since last DTC clear ---------------------------- 7859 [0x001EB3] P201500: Intake Manifold Runner Position Sensor/Switch Circuit, Range/Performance Status bits: 1 Priority: 2 Frequency: 1 Unlearning index: 255 Odometer: 332486 km Date, time: 2008.05.27 01:25:21 Engine RPM: 0 rpm Calculated engine load value: 0.00 % Vehicle speed: 0 km/h Engine coolant temperature: 7 ℃ Engine oil temperature: 10 ℃ Distance traveled with MIL on: 99 kPa Klemme 30 voltage: 11 Paramteric values: 20 96 28 13 3B 00 00 11 88 00 00 10 2A 00 00 11 DF 03 C5 11 DE 01 5A 11 DD 07 45 12 15 Status: Test failed, Test failed (current drive cycle), Pending, Test failed since last DTC clear ============================ 05. Authorization system for access and starting the engine No DTC found. ============================ 08. Heater and climate No DTC found. ============================ 0D. Slide Door Left (VW TP2.0) No DTC found. ============================ 15. SRS No DTC found. ============================ 16. Steering column No DTC found. ============================ 17. Dashboard17. Dashboard DTCs: 1 ---------------------------- 1771 [0x06EB] Headlight range control unit-J431 Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request ============================ 42. Driver door electronic equipment No DTC found. ============================ 46. Central comfort systems module (VW TP2.0)46. Central comfort systems module (VW TP2.0) DTCs: 1 ---------------------------- 0473 [0x01D9] Electromechanical parking brake control unit-J540; Electric parking / handbrake control unit-J540 Status: Pending fault present, Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request ============================ 47. Acoustic system No DTC found. ============================ 52. Front passenger door electronics No DTC found. ============================ 53. Parking brake53. Parking brake DTCs: 1 ---------------------------- 3182 [0x0C6E] Status: Pending fault present, Pending fault present during this driving cycle, Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request ============================ 56. Head unit (MMI) (VW TP2.0) No DTC found. ============================ 62. Rear left door electoronics (VW TP2.0) No DTC found. ============================ 72. Rear right door electronics (VW TP2.0) No DTC found. ============================ 77. Telephone No DTC found. ============================ 78. Slide Door Right (VW TP2.0) No DTC found.

Help please. New member, first post. A4 B8 Quattro Avante 2.0 TDI 6Sp manual 170HP engine UK RHD '09 won't turn over. Battery was on last legs. Whilst the dash lit up, it wouldn't turn over when I pressed the key in. So had a new battery fitted today but was told as I don't have stop/start it didn't need to be coded. Is that correct? I have tried another ignition switch after it suddenly started on the 10th push on the key on the original one and it was giving the ignition switch warning. Checked all the fuses on the drivers (RHS) of the dash as well as the fuses in front of the windscreen in the engine dept. Tried swapping the 4 X 404 relays about in pairs. Tested all seven relays in the pic attached and they all click when +12v is applied though I haven't measured the resistance between the relay points. The steering lock solenoid releases. Am confident the starter and main solenoid are not the issue but would like to know which pin on which underbonnet relay would activate the starter solenoid so I can test it before deciding whether on not to take the starter off the car? I thought there was a switch on the clutch pedal but have also read it's built into the clutch master cylinder. Can anyone please clarify? I would like to test the solenoid before removing the starter which looks like it requires major surgery to get it out. Do Audi start with the starter then build the rest of the car around it? I can't see any way of giving the starter a good dunt in case the brushes are sticking. I've also read that there is a fuse or relay on the +ve lead where it connects to the battery in the boot? Is it a fuse or a relay? I assume I can safely bypass it by bridging it? Am I missing anything? Any suggestions? Am in desperate need for this to be running by tomorrow night. Any help greatly appreciated. Thanks.