I have an Audi A6 V6 2.8l engine has no spark and signal on injectors have changed crankshaft and camshaft position sensors if I give a negative signal to a green wire on the ecm the vehicle starts

Have you plugged in an OBDII reader to get a list of trouble codes?

Hi Willem, Code 18 is a Crankshaft position sensor/Camshaft position sensor............ P0018
Crankshaft Position Camshaft Position/Correlation (Bank 2 Sensor A)
Crankshaft Position Sensor car not starting coil spark

Camshaft Position Sensor P0340 Testing and Replacement HD

Is the check engine light lit ? Any DTC'S - diagnostic trouble codes ? What engine ? 4.3 L vortex . Leaking fuel pressure regulator under the upper intake manifold . Leaking fuel injectors ! Ignition timing problem . How does the engine run ? Who installed the plugs an wires ? are they right ? Fuel pressure leak down test, fuel injector balance testing . Check distributor drive gear an slop in the shaft . Did you have distributor out ? Is it in the proper position ? What cylinder is misfiring ? engine mechanical problem ! What do spark plugs look like ? fouled , soaked with fuel . Do a engine compression test .
The camshaft drives the distributor shaft which rotates providing a spark to the correct cylinder by way of the cap and rotor. The camshaft position sensor functions much like the crankshaft sensor previously described but provides only a 1x signal to the VCM. That is, for every 2 rotations of the crankshaft, there is 1 rotation of the camshaft. Note that the CMP sensor will not affect driveability. The sole purpose of the CMP sensor is to provide the VCM with the necessary information for the misfire DTCs.

Definition of Diagnostic Trouble Code P1345 Audi: Ignition Coil Power Output Stage 3 Short to Ground BMW: Misfire Cylinder 2 with Fuel Cut-Off Buick: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Cadillac: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Chevrolet: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Ford: Cylinder Discrimination Signal (Signal From Camshaft Position Sensor) GMC: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Isuzu: Crankshaft Position - Camshaft Position Correlation Kia: No SGC Signal (1.6L) Lexus: Variable Valve Timing / CMP Sensor Range / Performance Lincoln: Cylinder Discrimination Signal (Signal From Camshaft Position Sensor) Mazda: Cylinder Discrimination Signal (from CMP sensor) Mercury: Cylinder Discrimination Signal (Signal From Camshaft Position Sensor) Oldsmobile: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Pontiac: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Saturn: Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Toyota: Variable Valve Timing / CMP Sensor Range / Performance Volkswagen: Ignition Coil Power Output Stage 3 Short to Ground

get a HAYNES repair manual, tells you what all sensors do ! the crankshaft sensor sends info to the SBEC, reguarding engine crankshaft position. the camshaft sensor reads camshaft position, sends a coded signal to the SBEC, which uses this info to determine whether the fuel injectors and ignition coils are correctly synchronized !

Description & Operation

2.5L Engines
On the 2.5L 4cylinder engine the Camshaft Position (CMP) sensor is located in the distributor.
The sensor contains a Hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects a rotating pulse ring (shutter) on the distributor shaft. The pulse ring rotates 180 degrees through the sync signal generator. Its signal is used in conjunction with the Crankshaft Position (CKP) sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.
When the leading edge of the pulse ring (shutter) enters the sync signal generator, the following occurs: The interruption of magnetic field causes the voltage to switch high resulting in a sync signal of approximately 5 volts. When the trailing edge of the pulse ring (shutter) leaves the sync signal generator, the following occurs: The change of the magnetic field causes the sync signal voltage to switch low to 0 volts. 4.0L

The Camshaft Position Sensor (CMP) on the 4.0L 6cylinder engine is bolted to the top of the oil pump drive shaft assembly. The sensor and drive shaft assembly is located on the right side of the engine near the oil filter.
The CMP sensor contains a Hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects a rotating pulse ring (shutter) on the oil pump drive shaft. The pulse ring rotates 180 degrees through the sync signal generator. Its signal is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.
When the leading edge of the pulse ring (shutter) enters the sync signal generator, the following occurs: The interruption of magnetic field causes the voltage to switch high resulting in a sync signal of approximately 5 volts.
When the trailing edge of th4.7L

The Camshaft Position Sensor (CMP) on the 4.7L V8 engine is bolted to the front/top of the right cylinder head.
The CMP sensor contains a Hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects notches located on a tone wheel. The tone wheel is located at the front of the camshaft for the right cylinder head. As the tone wheel rotates, the notches pass through the sync signal generator. The pattern of the notches (viewed counter-clockwise from front of engine) is: 1 notch, 2 notches, 3 notches, 3 notches, 2 notches 1 notch, 3 notches and 1 notch. The signal from 5.7L V8 Engines

The Camshaft Position Sensor (CMP) on the 5.7L V-8 engine is located below the generator on the timing chain / case cover on the right/front side of engine.

Fig.

The CMP sensor is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders. The sensor generates electrical pulses. These pulses (signals) are sent to the Powertrain Control Module (PCM). The PCM will then determine crankshaft position from both the camshaft position sensor and crankshaft position sensor.
The tone wheel is located at the front of the camshaft (2). As the tone wheel rotates, notches (3) pass through the sync signal generator.
When the cam gear is rotating, the sensor will detect the notches. Input voltage from the sensor to the PCM will then switch from a low (approximately 0.3 volts) to a high (approximately 5 volts). When the sensor detects a notch has passed, the input voltage switches back low to approximately 0.3 voltsthe CMP sensor is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinderse pulse ring (shutter) leaves the sync signal generator, the following occurs: The change of the magnetic field causes the sync signal voltage to switch low to 0 volts

DTC P0016 - Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
The crankshaft position sensor (CKP) and Camshaft position sensor (CMP) work in harmony to control the spark/fuel delivery and timing. They both consist of a reluctor, or tone, ring which passes over a magnetic sensor, which generates a voltage, indicating position.

The crankshaft sensor is part of the primary ignition system and functions as the "trigger". It detects the position of the crankshaft relays that information on to the PCM or the ignition module (depending on the vehicle) to control spark timing. The Camshaft position sensor detects the position of the camshafts and relays the information to the PCM. The PCM uses the CMP signal to identify the beginning of the injector sequence. What ties these two shafts and their sensors together is the timing belt or chain. The cam and crank should be precisely timed together. If the PCM detects that the Crank and Cam signals are out of time by a specific number of degrees, this P0016 code will set.

Symptoms of a P0016 will or may include:
Malfunction Indicator Lamp (MIL) illumination
The engine may run but with reduced performance
The engine may crank but not start
The engine may exhibit a rattle near the harmonic balancer indicating the tone ring is damaged
The engine may start and run, but poorly

Causes may include:
Timing chain stretched, or timing belt skipped a tooth due to wear
Misalignment of timing belt/chain
Tone ring on crankshaft slipped/broken
Tone ring on camshaft slipped/broken
Bad crank sensor
Bad cam sensor
Damaged wiring to crank/cam sensor
Timing belt/chain tensioner damaged

Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day.

NEED HAVE VECHICLE CODE SCANNED FIRST LOOK FOR FAULT CODES MANY THINGS WILL CAUSE NO STARTING,LIKE BAD CRANKSHAFT POSITION SENSOR.FAULTY CAMSHAFT POSITION SENSOR,BAD SPARK PLUGS FOULED OUT BY FLOODING ENGINE DUE TO LEAKING FUEL INJECTORS,BAD ENGINE COOLANT TEMPERATURE SENSOR,BAD MASS AIR FLOW SENSOR.FAULTY ECM. CODE SCAN VECHICLE FIRST.IF NO FAULT CODES CAME UP YOU COULD HAVE FAULT IN FUEL SYSTEM, COULD HAVE STOPPED UP FUEL FILTER,BAD FUEL PUMP RELAY OR FUSE THE FUEL PUMP COULD BE FAULTY. TURN IGNITION SWITCH TO ON POSITION LISTEN FOR FUEL PUMP OPERATION IN FUEL TANK, YOU SHOULD HEAR FUEL PUMP RUN FOR FEW SECONDS THEN TURN OFF.IF NO FUEL PUMP BAD MORE LIKELY BUT CHECK FUSE AND RELAY FIRST BEFORE BUYING NEW FUEL PUMP.DONT BUY NEW PARTS HAVE VECHICLE CODE SCANNED FIRST USING DIAGNOSTIC SCANNER YOU COULD HAVE BAD CONTAMINATED FUEL.

CAMSHAFT POSITION SENSOR

I have a 1995 AUDI A6 QUATTRO, and it had similar problems which the AUDI repair shop had to fix.

Crankshaft and Camshaft Position Sensors Camshaft Position Sensor Engine timing is determined from the relationship between the crankshaft and camshaft. This relationship is maintained by a timing chain or timing belt. The Engine Management System does not control engine timing but it does monitor the relative position and speed of these shafts by monitoring signals generated by sensors. The Engine Management System (EMS) uses signals generated by the camshaft position sensor to synchronize fuel injection to the valve sequence and for the on-board diagnostic procedure for misfire detection. The EMS energizes the injector at or near the time the intake valve opens. For misfire diagnosis, the EMS compares the number of camshaft sensor reference pulses and the number of crankshaft position sensor reference pulses received. If the EMS receives an incorrect number of pulses Diagnostic Trouble Codes (DTC’s) should be stored in the EMS.
If the camshaft position sensor or circuit is faulty most engines will start. Some engine management systems will then default to a pre-programmed injector firing sequence. All injectors may be energized simultaneously or all of the injectors on one bank may be energized at the same time. If the CMP data is required for misfire detection and reliable CMP data is not present misfire detection would probably be suspended.
Related Symptoms The following symptoms can be caused by an intermittent wiring connection or faulty signal to the EMS:

• Extended crank time with a cold engine
• Intermittent rough running
• Unstable idle
• Bucking
• Hesitation
• Stumble
• Chuggle
• Poor fuel economy
• Stalling on acceleration

Crankshaft Position Sensor Engine speed is a very important input to the Engine Management System (EMS). Crankshaft speed and position are the basis for many calculations made by the computer. Crankshaft position values are transmitted to the computer by pickup coils also known as Permanent Magnet (P/M) generators, hall-effect sensors or optical sensors. The Crankshaft Position Sensor (CKP) also known as engine speed sensor is located in close proximity to the crankshaft.
In addition the EMS uses minute variations in the CKP sensor data to determine engine misfire. The EMS uses this information in conjunction with the camshaft position sensor to perform misfire diagnostics.
Related Symptoms: No Start/Intermittent Start Condition – Can be caused by a faulty crankshaft position sensor due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit