Ran VAG COM on S4 - some faults on engine module?

[Stevo]

4 Faults Found:
17862 - Exhaust Gas Temp Sensor 1 (G235): Short to Ground
P1454 - 35-10 - - - Intermittent
17977 - Cruise Control Switch (E45): Implausible Signal
P1569 - 35-10 - - - Intermittent
17870 - Exhaust Gas Temp Regulation for Bank 2: Implausible Signal
P1462 - 35-10 - - - Intermittent
17864 - Exhaust Gas Temp Regulation for Bank 1: Limit Reached
P1456 - 35-10 - - - Intermittent

I have noticed a couple of times now that when running with the Cruise control on, i would try and accelerate using the slide-to-left switch on the CC stalk and it would knock me out of CC mode and i would not be able to go back and set CC back on until i actually stopped the car and removed the keys from the ignition, then it would reset itself.

The other codes i'm not sure of but i ran a couple of logged runs with VAGCOM group 115:

Time stamp; Engine speed; Engine load; Spec'd Boost; Actual Boost

94.26 3760 118.8 1650 1470
94.56 3800 127.8 2160 1560
94.87 3840 149.6 2150 1840
95.17 3920 167.7 2140 2030
95.47 3960 175.2 2140 2140
95.77 4040 176.7 2130 2180
96.08 4080 177.4 2120 2180
96.38 4160 175.9 2120 2140
96.69 4240 173.7 2110 2120
97 4280 171.4 2100 2110
97.32 4360 169.9 2090 2100
97.63 4400 169.2 2090 2090
97.95 4480 169.2 2080 2100
98.27 4520 167.7 2070 2090
98.59 4600 167.7 2060 2080
98.91 4640 166.2 2050 2070
99.23 4720 163.9 2040 2060
99.56 4760 161.7 2030 2030
99.89 4840 160.9 2020 2020
100.22 4880 160.9 2010 2020
100.55 4880 21.1 1000 1720
100.86 4400 9 1000 1250

and group 002:

Time stamp; Engine speed; Engine load; Injection time; Mass air flow

273.8 1800 90.2 9.52 51.67
274.1 2520 100.8 10.54 80.97
274.41 3280 125.6 12.92 135.14
274.72 4160 154.1 15.64 205.47
275.06 5280 157.9 19.04 240.61
275.42 5960 97.7 8.5 162.06
275.77 5400 11.3 1.36 2.47
276.08 3680 107.5 12.24 137.56
276.38 3960 145.9 14.96 193.22

Do these figures look okay as i've not really noticed any lack of performance but i'm worried about the error codes and any costly repairs.

The car is running APR chip on optimax.

[Dippy]

Stevo,

Those VAG COM logs look OK to me, but clearly you must have a fault in your CC and also G235.

[tartan_rob]

I'm not sure the maps look okay. The car is chipped or at least boost pressure has been increased from 1.9bar (over absolute) to 2.1bar. Your max air flow has only reached 240gal/sec. I have std S4 running 1.8 boost and get the same air volume figures. Your performance must be down, I'd go for MAF and/or DV's. The EGT will definately make a massive difference to performance - and I mean a big difference. EGT too low, ECU thins out mixture to heat up exhaust gases, EGT too high and the ECU will increase fuelling and alter timing to bring it down. In either case you are not burning an optimum mixture or initiating the explosion at the correct time. I'd start with EGT.

[Stevo]

thing is i cleared those codes from 2 weeks ago and got these codes again:

2 Faults Found:
17861 - Exhaust Gas Temp Sensor 1 (G235): Open or Short to Plus
P1453 - 35-10 - - - Intermittent
17977 - Cruise Control Switch (E45): Implausible Signal
P1569 - 35-10 - - - Intermittent

The EGT code is slightly different this time.

??????????????

Confused!

[S2tuner]

@Stevo: you need to do the logs at WOT in 3rd gear from 2000 through the rev limiter without letting off the gas, then post them here and we'll be able to tell you what's wrong... The EGT fault code could be due to a mapping problem, can u post logs from group 003 (or whichever has the injector opening time in ms, maybe it's 100-something?

HTH,

Mihnea

[Stevo]

I wonder if i'd get these fault codes due to running BP ultimate ron 97 on the optimax ron 98 program???? the other day i also had to use Esso ron 97
Sometimes i also run optimax on the stock program, this must be okay surely???

WOT in third gear thru rev limiter! I rarely hit the red line, dont like doing this.

I'll be back with the logs.

Thanks for the responses.

Steve.

[Stevo]

Okay did 2 runs in third gear from 2000 rpm in optimax program:

Time speed; Engine speed; Engine load; Injection time; Mass air flow

0.01 1960 15.8 2.04 9.33
0.3 1960 15.8 2.04 9.33
0.6 1960 15.8 2.04 9.19
0.91 1960 16.5 2.04 9.97
1.21 1960 20.3 2.72 13.83
1.51 2000 23.3 2.72 13.89
1.81 2000 23.3 2.72 13.75
2.11 2000 23.3 2.72 13.86
2.41 2000 26.3 3.06 17.72
2.72 2040 28.6 3.4 17.5
3.02 2040 30.1 3.4 19.36
3.32 2080 35.3 3.74 21.28
3.62 2120 33.1 3.74 20.64
3.92 2160 33.1 3.74 21.53
4.22 2160 33.8 3.74 21.03
4.53 2200 54.1 8.16 74.03
4.83 2240 82 9.18 59.64
5.13 2360 97.7 10.2 74.86
5.43 2480 114.3 11.56 92.5
5.73 2600 132.3 13.26 110.19
6.03 2760 154.1 14.96 136.47
6.34 2920 178.2 17 164.5
6.64 3120 191.7 19.04 184.19
6.94 3320 191.7 19.72 192.5
7.24 3520 191.7 21.42 194.19
7.54 3680 181.2 19.04 192.31
7.84 3880 179.7 19.72 201.36
8.15 4040 178.2 20.06 211.03
8.46 4200 176.7 20.4 213.89
8.77 4360 172.2 19.72 218.56
9.09 4520 168.4 19.04 221.78
9.41 4720 167.7 19.38 229.33
9.74 4880 163.9 19.04 229.92
10.07 5040 157.9 18.36 230.42
10.41 5200 156.4 18.7 234.72
10.76 5360 154.1 18.7 241.5
11.11 5520 152.6 18.36 244.44
11.46 5680 151.1 18.36 252.61
11.82 5800 149.6 18.36 247.97
12.19 5920 146.6 18.02 254
12.54 6080 142.1 17 252
12.93 6200 139.8 15.98 254.78
13.3 6360 136.8 15.98 256.92
13.67 6480 133.8 15.64 252
14.06 6600 130.8 14.28 249.94
14.43 6720 128.6 13.94 253.39
14.81 6840 127.1 13.6 254.06
15.19 6960 126.3 13.6 256.19
15.56 7040 124.1 12.92 256.19
15.93 6720 12 1.36 2.22
16.3 5600 98.5 10.88 187.22
16.65 5640 151.1 18.7 255.39
17.01 5640 82 6.46 116.75
17.35 5240 9.8 1.36 4.69
17.67 4760 9.8 1.36 11.69
18 4680 9.8 1.36 13.08
18.31 4640 9.8 0 13.83
18.64 4600 9.8 0 13.42
18.96 4560 9.8 0 14.08
19.27 4560 9.8 0 14.19
19.6 4520 9.8 0 14.03
19.92 4520 9.8 0 13.44
20.24 4480 10.5 0 14.14
20.55 4440 10.5 0 13.14
20.87 4400 10.5 0 13.42
21.18 4400 10.5 0 13.86
21.5 4360 10.5 0 14.06
21.81 4320 10.5 0 13.47
22.12 4320 10.5 0 13.47
22.43 4280 10.5 0 13.36
22.74 4240 10.5 0 13.56
23.05 4240 10.5 0 13.56
23.36 4160 10.5 0 13.42
23.66 4160 10.5 0 13.36
23.97 4120 10.5 0 13.44
24.28 4080 10.5 0 12.86
24.58 4040 10.5 0 13.22
24.88 4040 10.5 0 12.81
25.18 4000 10.5 0 13.36
25.49 3960 10.5 0 12.67
25.79 3920 10.5 0 12.92
26.09 3920 10.5 0 12.42
26.39 3880 10.5 0 12.75
26.69 3840 10.5 0 12.75
26.99 3840 11.3 0 12.69
27.3 3800 11.3 0 12.47
27.6 3760 10.5 0 12.14
27.9 3720 11.3 1.7 12.33
28.2 3720 44.4 5.78 53.83
28.5 3720 63.2 6.8 74.44
28.8 3720 44.4 4.08 45.03
29.11 3720 30.8 3.06 29.64
29.41 3720 24.8 3.06 25.75
29.71 3680 22.6 2.72 23.67
30.01 3680 20.3 2.38 22.83
30.31 3680 20.3 2.38 22.67
30.61 3640 22.6 2.72 24.14
30.92 3640 22.6 2.72 24.53
31.22 3640 21.8 2.72 23.44
31.52 3600 19.5 2.38 21.58
31.82 3600 20.3 2.38 21.53
121.22 760 18 2.38 4.22
121.52 800 18 2.38 4.19
121.82 760 18 2.38 4.25
148.78 1920 58.6 6.12 33.28
149.08 1960 56.4 5.78 31.56
149.37 2000 36.1 3.74 18.92
149.69 2000 40.6 4.42 23.78
149.99 2040 41.4 4.42 24.56
150.29 2080 39.8 4.08 24.56
150.59 2120 39.1 4.42 24.42
150.99 2080 25.6 2.38 11.75
151.29 2080 12.8 1.7 6.92
151.59 2080 11.3 1.7 6.58
151.9 2040 11.3 0 6.78
152.19 2000 11.3 1.7 7.06
152.5 2040 11.3 1.7 7.03
152.8 2040 15.8 2.04 11.22
153.11 2000 18.8 2.38 11.36
153.4 2000 19.5 2.38 13.78
153.71 2080 69.2 8.16 49.86
154 2120 83.5 9.18 56.86
154.3 2200 100.8 10.54 71.36
154.61 2320 115 11.56 85.61
154.92 2440 133.8 13.6 105.31
155.22 2600 155.6 15.3 128.44
155.52 2760 177.4 17 153.78
155.82 2920 191.7 19.04 175.11
156.12 3120 191.7 19.38 184.19
156.41 3320 191.7 18.7 181.83
156.73 3480 190.2 18.7 194.53
157.03 3680 183.5 19.72 194.58
157.33 3800 181.2 19.72 204.25
157.63 3960 179.7 20.4 208.06
157.94 4160 177.4 20.4 213.89
158.25 4280 172.2 19.38 215.42
158.56 4480 172.2 19.38 223.17
158.89 4640 168.4 19.38 227
159.2 4760 166.2 19.38 229.42
159.54 4960 161.7 18.7 231.33
159.88 5080 157.1 18.7 230.44
160.22 5240 157.1 19.04 236.64
160.56 5400 154.9 19.04 245
160.91 5520 154.9 19.04 248.5
161.27 5680 151.1 18.36 250.06
161.63 5760 148.1 18.02 251.92
161.99 5920 145.1 17.68 248.5
162.34 6040 143.6 17 252.69
162.73 6200 140.6 16.66 254.78
163.09 6320 138.3 16.32 254.78
163.48 6440 136.1 15.64 254.78
163.86 6560 133.1 14.96 256.92
164.24 6680 131.6 14.62 253.39
164.6 6760 129.3 14.28 254.06
164.99 6880 128.6 13.94 256.92
165.37 6960 78.2 6.12 156.58
165.73 5480 97.7 11.56 160.53
166.08 5520 148.1 18.02 256.81
166.43 5600 154.1 19.04 250.56
166.79 5680 150.4 18.36 246.94
167.14 5720 150.4 18.36 251.92
167.49 5560 17.3 2.04 0
167.83 5000 9 1.7 10.78
168.14 4160 53.4 9.52 90.81
168.44 4040 117.3 12.24 159.17
168.75 4040 135.3 11.9 165.42
169.05 4040 47.4 4.42 39.31
169.35 4040 33.8 3.4 36.94
169.65 4040 25.6 2.72 29.5
169.96 4040 23.3 2.72 26.92
170.26 4000 23.3 2.72 28.06
170.56 4000 18.8 2.04 20.86
170.86 3960 22.6 2.72 26.14
171.16 3960 17.3 2.04 20.5
171.47 3960 18 2.04 20.11
171.77 3920 18 2.04 20.75
172.07 3920 30.8 3.4 36.94
172.37 3920 45.1 5.1 53.67
172.67 3920 39.1 4.08 45.11
172.98 3880 38.3 4.08 45
173.28 3880 35.3 3.74 40.11
173.58 3880 36.8 3.74 42.5
173.88 3880 38.3 4.08 43.33
174.18 3880 45.1 5.1 53.22
174.48 3880 46.6 4.76 53.89
174.79 3880 43.6 4.76 50.92
175.09 3880 37.6 3.74 41.69
175.39 3880 36.1 3.74 41
175.69 3840 28.6 3.06 31.14
175.99 3840 27.8 3.06 31.17
176.29 3840 27.1 3.06 30.58
176.6 3840 32.3 3.74 36.94
176.9 3800 33.1 3.4 37.28
177.2 3800 32.3 3.4 35.92
177.5 3800 30.8 3.4 34.06
177.8 3760 33.1 3.4 36.97
178.1 3800 31.6 3.4 35.22
178.41 3760 31.6 3.4 35.58
178.71 3760 30.8 3.4 34.31
179.01 3760 31.6 3.4 34.92
179.31 3720 31.6 3.4 34.67
179.61 3720 32.3 3.4 36.31
179.91 3720 31.6 3.4 35.31
180.22 3680 18.8 2.04 18.06
180.52 3720 10.5 1.36 10.78
180.82 3680 10.5 1.36 10.81
181.12 3680 10.5 0 11.36
181.42 3640 10.5 0 11.89
181.73 3640 10.5 0 11.58
182.03 3600 10.5 0 11.92

[tartan_rob]

I'd switch off cruise control and then clear your codes. I bet you any money it is your EGT. When you start the car up on a cold morning the revs whould sit around 1100/1200 for 10 or so secs. When my EGT sensor went (same fault codes), I started up from cold and the initial idle was below 1k revs.

I run Shell optimax (and have done since I had the car 18 months ago) and I have no issues. You want to run the car on the highst octane fuel you can. It has less impurities in it and therefore better for your car (and better bhp as a result)....there is one EGT on each bank so the code relates to a specific bank, they are both the same part number but obviousely you have to change the correct one.

[Stevo]

Rob,

when you say EGT is that exhaust gas temp sensor, if so where are these located exactly and is it a DIY or a garage job?

[tartan_rob]

Stevo - it depends which one, open the bonnet, as you look down the car and you can read v6 Bi-Turbo, look at the left bank then work backwards towards the bulkhead, look down and you'll see the exhaust manifold covered by a heat sheild, the probe that is sticking out is your left bank EGT sensor and a piece of pish to change. To locate your right one you'll have the loosen the turbo off which is no easy job. It was my right one that went and one seeing that the job was a nightmare I tried to contact Audi to get the beast booked in, they told me they'd have to order another sensor so the other one I had bought was wasted. I took my chances and cut the cables joining the old probe to the new control unit of the new sensor. Not the best job but it works and no longer registers a fault.:)

Your best bet is to register with Erwin (http://erwin.audi.de/) and get the AGB engine manual, in their you can cross reference the fault code to the correct description and it'll also detail how to change the unit. I have lost my yearly subscription and not willing to pay the 18euro's to renew until I need it, otherwise I'd tell you what side it was...

[Stevo]

Okay,

I cleared the codes and checked the car at cold startup and it idles at about 1200 rpm for a while then back to around 750rpm

If it was a persistent fault (EGT) would it show up again on VAGCOM now that i've cleared them?
If the MAF sensor goes would that give me an indicative fault code thru VAGCOM?

Steve.

[Druggie]

4 Faults Found:
I have noticed a couple of times now that when running with the Cruise control on, i would try and accelerate using the slide-to-left switch on the CC stalk and it would knock me out of CC mode and i would not be able to go back and set CC back on until i actually stopped the car and removed the keys from the ignition, then it would reset itself.

i have the same issue with my cruise... Do you know what could be causing it?

[Druggie]

4 Faults Found:
I have noticed a couple of times now that when running with the Cruise control on, i would try and accelerate using the slide-to-left switch on the CC stalk and it would knock me out of CC mode and i would not be able to go back and set CC back on until i actually stopped the car and removed the keys from the ignition, then it would reset itself.

i have the same issue with my cruise... Do you know what could be causing it?

[Stevo]

Well i had the DV's off this afternoon to check them and noticed that the right hand side DV had a small amount of fresh oil skim on the inside of one of the main outlet/inlet pipes???

[DavidR]

That, I believe, is normal Steve. The breather system sometimes means that there is a small amount of oil in there - it can alternate sides too.

Re the EGT, I had replaced one earlier (I cannot remember which side it was done under warranty) and the first I knew about it was at the service when they told me - no symptoms of it being out - no idling issues etc. Another Audi weak spot perhaps.

Re MAF, the figures above look about right for the MAF, I found that when the MAF broke (last year) the actual boost was way below expected and the car felt really sluggish.