ECU or something else?

[Steve Barnes]

Hi all, just after some advice. I've been looking at a car (2006, 2.0l diesel) for a friend today which has had a diagnoses of ECU failure, however the car runs flawlessly despite it having engine management light, ABS and coolant temp lights on when I inspected it.



I used a scanner to look for codes which cleared the lights, but gave the following..

Is there anywhere I should be looking or tests I can do to find where the fault lies?

I am thinking there maybe a bad ground or cable break somewhere as opposed to ECU failure given everything is working as it should.



Car Scanner ELM OBD2
DTC report
Selected brand: Audi

============1==============
P2100
Raw code: 2100
ECU: OBD-II
Status: Confirmed
OBDII: Throttle actuator control (TAC) motor - open circuit
============2==============
P0117
Raw code: 0117
ECU: OBD-II
Status: Confirmed
OBDII: Engine coolant temperature (ECT) sensor - low input
Audi: Engine Coolant Temperature (ECT) Sensor Circuit Low Voltage
============3==============
P2102
Raw code: 2102
ECU: OBD-II
Status: Confirmed
OBDII: Throttle actuator control (TAC) motor - circuit low
============4==============
0470
Raw code: 01D6
ECU: 19. CAN Gateway
Status: Pending fault present, Pending fault present during this driving cycle, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Common concern data bus Comfort in single-wire data transfer mode; Group data bus convenience in a single wire
============5==============
0290
Raw code: 0122
ECU: 03. ABS control unit
Status: Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory
Audi: Rear Left Wheel Speed Sensor-G46; Rear left speed sensor-G46; Throttle valve potentiometer-G69 signal too small
============6==============
1435
Raw code: 059B
ECU: 03. ABS control unit
Status: Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Brake Pressure Sensor 1-G201; Brake pressure sender 1-G201
============7==============
19557
Raw code: 4C65
ECU: 01. Engine control unit
Status: Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P3101 Intake manifold flap actuator motor-V157: open circuit / short to ground; Intake manifold flap motor-V157 Open circuit / short circuit to earth
============8==============
17075
Raw code: 42B3
ECU: 01. Engine control unit
Status: Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P0691 Radiator Fan Control 1: Short to Ground; Cooling fan control 1 short circuit to ground
============9==============
16501
Raw code: 4075
ECU: 01. Engine control unit[Archive (inactive)]
Status: Validated and stored in non volatile memory
Audi: P0117 Coolant Temperature Sensor-G62: Signal Too Low; Coolant temperature sender G62 signal too small
============10==============
19558
Raw code: 4C66
ECU: 01. Engine control unit
Status: Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P3102 Intake manifold flap actuator motor-V157: no signal; Intake manifold flap motor-V157 no signal
============11==============
17056
Raw code: 42A0
ECU: 01. Engine control unit
Status: Test has not been completed, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P0672 Glow plug for cylinder 2-Q11: electrical failure; Glow plug cylinder 2-Q11 electrical fault in the circuit
============12==============
17057
Raw code: 42A1
ECU: 01. Engine control unit
Status: Test has not been completed, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P0673 Glow plug 3-Q12: malfunction in an electric chain; Glow plug cylinder 3-Q12 electrical fault in the circuit
============13==============
17058
Raw code: 42A2
ECU: 01. Engine control unit
Status: Test has not been completed, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P0674 4-Q13 glow plug, electrical failure; Glow plug cylinder 4-Q13 electrical fault in the circuit
============14==============
0483
Raw code: 01E3
ECU: 08. Heater and climate
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
Audi: Auxiliary air heater control unit; Control unit for additional air heating
============15==============
16346
Raw code: 3FDA
ECU: 17. Dashboard
Status: Pending fault present during this driving cycle, Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Control block; Control unit
============16==============
0932
Raw code: 03A4
ECU: 42. Driver door electronic equipment
Status: Pending fault present, Test conditions are met, Validated and stored in non volatile memory
Audi: Driver Side Power Window Motor-V147; Motor window regulator driver's side-V147
============17==============
0361
Raw code: 0169
ECU: 7D. Additional heater (VW TP2.0)
Status: Pending fault present during this driving cycle, Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Heater, auxiliary heater-Z35; Heating element for additional heating-Z35; Bank1, fuel metering system 2 malfunction
============18==============
P2102
Raw code: 2102
ECU: OBD-II
Status: Pending
OBDII: Throttle actuator control (TAC) motor - circuit low
============19==============
P2100
Raw code: 2100
ECU: OBD-II
Status: Pending
OBDII: Throttle actuator control (TAC) motor - open circuit
============20==============
0470
Raw code: 01D6
ECU: 19. CAN Gateway
Status: Pending fault present, Pending fault present during this driving cycle, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Common concern data bus Comfort in single-wire data transfer mode; Group data bus convenience in a single wire
============21==============
1435
Raw code: 059B
ECU: 03. ABS control unit
Status: Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Brake Pressure Sensor 1-G201; Brake pressure sender 1-G201
============22==============
19558
Raw code: 4C66
ECU: 01. Engine control unit
Audi: P3102 Intake manifold flap actuator motor-V157: no signal; Intake manifold flap motor-V157 no signal
============23==============
19557
Raw code: 4C65
ECU: 01. Engine control unit
Status: Validated fault present at time of request
Audi: P3101 Intake manifold flap actuator motor-V157: open circuit / short to ground; Intake manifold flap motor-V157 Open circuit / short circuit to earth
============24==============
17075
Raw code: 42B3
ECU: 01. Engine control unit
Status: Validated and stored in non volatile memory, Validated fault present at time of request
Audi: P0691 Radiator Fan Control 1: Short to Ground; Cooling fan control 1 short circuit to ground
============25==============
0483
Raw code: 01E3
ECU: 08. Heater and climate
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
Audi: Auxiliary air heater control unit; Control unit for additional air heating
============26==============
16346
Raw code: 3FDA
ECU: 17. Dashboard
Status: Pending fault present during this driving cycle, Test conditions are met, Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request
Audi: Control block; Control unit
============27==============
0932
Raw code: 03A4
ECU: 42. Driver door electronic equipment
Status: Pending fault present, Test conditions are met, Validated and stored in non volatile memory
Audi: Driver Side Power Window Motor-V147; Motor window regulator driver's side-V147

 

[ahtcap]

Have you cleared the codes and re scanned? You may have some old codes stored that have already been sorted.

 

[Steve Barnes]

Yes I had cleared the codes, many of which went, there were 76 in total. These are the ones that remain.

The customers mot has just run out and as stated the main issue was the eml and abs lights which are now off but I have advised that these will probably return so the issues with ecu or whatever will need rectifying before it goes to mot.

I've been reading about relays and fuses causing issues so think this may be next port of call. What is the reset procedure on these for ECU? Figuring this maybe worth a shot as I don't know the history of the car. As stated everything works fine.

Also should I be looking at the throttle actuator motor as a possible culprit as this code is confirmed whereas most of the others are inhibited by something else if I'm reading this correctly.

 

[desertstorm]

It seems to have faults in many different areas, faulty glow plugs, ABS sensors , auxilliary heater,electric windows, radiator fan control, the comfort CAN in single wire, coolant temp sensors etc etc. A lot of these are not relavent to the ECU . I would scan it with a proper tool and clear the codes using VCDS. Some of the generic tools don't report the correct information and won't clear faults in some of the modules even though they say they have.
A lot of the faults could actually be genuine and the engine will run fine.