Exhaust gas temperature - Revision history

Nyet: /* Exhaust gas temperature measurement */

2014-06-03T16:59:17Z

Exhaust gas temperature measurement

← Older revision		Revision as of 16:59, 3 June 2014
Line 1:		Line 1:
	==Exhaust gas temperature measurement==		==Exhaust gas temperature measurement==

	[[VAG-COM]] blocks 034 and whatever else only display an internally calculated O2 sensor temperature, which is what most people think are real EGTs. That value may or may not have anything to do with the real EGTs or temperature at the primary O2 sensors; in fact, those temperature values are stored in 2 maps where the inputs are load and RPM.		[[VAG-COM]] blocks 034 and whatever else only display an internally calculated O2 sensor temperature (tabgbts), which is what most people think are real EGTs. That value may or may not have anything to do with the real EGTs or temperature at the primary O2 sensors; in fact, those temperature values are stored in 2 maps where the inputs are load and RPM.

	Block 112 is the only block where a real EGT value is displayed, and only when the actual EGTs exceed 945°C. This is only due to the design of the sensors and their electronic modules, which makes that they can only "read" 945-1035°C and that's all. So basically if all you see is 945 all the time, it means your actual EGTs never exceed 945.		Block 112 is the only block where a real EGT value (tats) is displayed, and only when the actual EGTs exceed 945°C. This is only due to the design of the sensors and their electronic modules, which makes that they can only "read" 945-1035°C and that's all. So basically if all you see is 945 all the time, it means your actual EGTs never exceed 945.

	If you see block 034 EGTs hitting 750 or 800 or 850, those values have never been, are not and will never be actual EGTs. The only real EGTs are in block 112. If you want to know what they are when they're below 945, then you have to use RS6 sensors with adequate programming, so you get a range of -40 to 1100°C and then you will know what your real EGTs are.		If you see block 034 EGTs hitting 750 or 800 or 850, those values have never been, are not and will never be actual EGTs. The only real EGTs are in block 112. If you want to know what they are when they're below 945, then you have to use RS6 sensors with adequate programming, so you get a range of -40 to 1100°C and then you will know what your real EGTs are.

Adam T at 05:19, 11 March 2013

2013-03-11T05:19:00Z

← Older revision		Revision as of 05:19, 11 March 2013
Line 74:		Line 74:

	===Physical construction===		===Physical construction===
	The measuring sensor consists of a thermocouple of unknown type. This thermocouple probe is attached to a control unit by means of a heat-resistant insulated cable with stainless steel over-braid shield.		The measuring sensor consists of a thermocouple of unknown type which is placed into the exhaust stream and held into the exhaust manifold by a M12x1mm thread retainer. This thermocouple probe is attached to a control unit by means of a heat-resistant insulated cable with stainless steel over-braid shield. The sensor electrical connections are keyed such that bank 1 sensor cannot be accidentally connected to the bank 2 engine harness connector.

	===Electronics design===		===Electronics design===
Line 85:		Line 85:

	===Substitute function and self-diagnosis===		===Substitute function and self-diagnosis===
			The ECU evaluates the sensor output to determine the sensor integrity provided the control bit '''B_CDAT''' has been set true. The error condition must exist for three seconds (defined by '''TVEATSS''') for the sensor to be flagged with an error code. The condition will be reset after 3 seconds (defined by '''TVEATSR''') of error free sensor operation. If a sensor has been determined to be faulty the ECU will set an error bit true. '''E_ATS''' for bank 1 (G235) or '''E_ATS2''' for bank 2 (G236).
⚫	~~The ECU is capable of producing four unique fault codes for various error a sensor fault states.~~ In the event of a sensor fault the ECU will fail-over to the working sensor to provide enrichment. In the event that both sensors have faults the ECU will fail over to an EGT limp mode where emergency enrichment
	characteristic (engine speed-dependent) is utilized. The error condition must exist for three seconds ('''TVEATSS''') for the sensor to be flagged with an error code and produce one of the following DTCs. The condition will be reset after 3 seconds ('''TVEATSR''') of error free sensor operation.

		⚫	In the event of a sensor fault the ECU will fail-over to the working sensor to provide enrichment. In the event that both sensors have faults the ECU will fail over to an EGT limp mode condition where emergency enrichment characteristic (engine speed-dependent) is utilized.
⚫	====Exhaust gas temperature sensor (1 or 2) Open/Short to B+:====

			====Fault code generation====
			The ECU is capable of producing four unique fault codes provided the control bit '''B_CDAT''' has been set true.

		⚫	=====Exhaust gas temperature sensor (1 or 2) Open/Short to B+:=====
	DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSMX'''. The stock value of '''TATSMX''' is 1034.51C. This correlates to an pulse width duty cycle of greater than 99% based on empirical data.		DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSMX'''. The stock value of '''TATSMX''' is 1034.51C. This correlates to an pulse width duty cycle of greater than 99% based on empirical data.

	DTC 17861 indicates this fault for bank 1 (G235) ('''B_MXATS''') while 17865 indicates this fault for bank 2 (G236) ('''B_MXATS2''').		DTC 17861 indicates this fault for bank 1 (G235) ('''B_MXATS''') while 17865 indicates this fault for bank 2 (G236) ('''B_MXATS2''').

	====Exhaust gas temperature sensor (1 or 2) Short to Ground:====		=====Exhaust gas temperature sensor (1 or 2) Short to Ground:=====
	DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is less than '''TATSMN'''. The stock value of '''TATSMN''' is 940.49C. This correlates to an pulse width duty cycle of less than 1% based on empirical data.		DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is less than '''TATSMN'''. The stock value of '''TATSMN''' is 940.49C. This correlates to an pulse width duty cycle of less than 1% based on empirical data.

	DTC 17862 indicates this fault for bank 1 (G235) ('''B_MNATS''') while 17866 indicates this fault for bank 2 (G236) ('''B_MNATS2''').		DTC 17862 indicates this fault for bank 1 (G235) ('''B_MNATS''') while 17866 indicates this fault for bank 2 (G236) ('''B_MNATS2''').

	====Exhaust gas temperature sensor (1 or 2) Implausible Signal:====		=====Exhaust gas temperature sensor (1 or 2) Implausible Signal:=====
	DTC is produce at engine idle when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSNP''' (default value of 950.00C) while the pre-catalytic converter modeled exhaust gas temperature ('''TABGM-W''' available to measure in block 034) is less than '''TDATSO''' (default value of 500C).		DTC is produce at engine idle ('''B_LL''') when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSNP''' (default value of 950.00C) while the pre-catalytic converter modeled exhaust gas temperature ('''TABGM-W''' available to measure in block 034) is less than '''TDATSO''' (default value of 500C).

	DTC 17863 indicates this fault for bank 1 (G235) ('''B_NPATS''') while 17867 indicates this fault for bank 2 (G236) ('''B_NPATS2''').		DTC 17863 indicates this fault for bank 1 (G235) ('''B_NPATS''') while 17867 indicates this fault for bank 2 (G236) ('''B_NPATS2''').

	====Exhaust gas temperature sensor (1 or 2) Signal Error:====		=====Exhaust gas temperature sensor (1 or 2) Signal Error:=====
	DTC is produce when the signal period is outside side of the period tolerance limit defined by '''DTPATS''' (default value of 50ms).		DTC is produce when the signal period is outside side of the period tolerance limit defined by '''DTPATS''' (default value of 50ms).

Adam T at 05:00, 11 March 2013

2013-03-11T05:00:23Z

← Older revision		Revision as of 05:00, 11 March 2013
Line 71:		Line 71:
	evaluation electronics.		evaluation electronics.

			==Sensor design==
	The measuring sensor and the control unit are
	permanently connected by means of a
	shielded, heat-resistant wire.

			===Physical construction===
	The evaluation electronics convert the signal
			The measuring sensor consists of a thermocouple of unknown type. This thermocouple probe is attached to a control unit by means of a heat-resistant insulated cable with stainless steel over-braid shield.
	which the measuring sensor generates into a

	pulse-width-modulated signal (PWM signal).
			===Electronics design===
	This is a square-wave signal with a fixed
			The evaluation electronics within the control unit convert the microvolt level thermocouple signal into a pulse-width-modulated signal (PWM signal) that can be interpreted by the ECU. The signal output consists of a square wave with a fixed frequency of 10Hz; meaning the ECU can be provided with 10 updated temperatures per second. The pulse width duty cycle is expressed as a percentage of signal high-time to the overall signal period. The sensor output ranges from a minimum pulse width of 5% to a maximum of 95%. The values above and below this range is reserved for the ECU to perform sensor diagnostics.
	frequency and a variable pulse duty factor.

	The pulse duty factor is expressed as a
			==ECU signal conversion==
	percentage. The measurement range extends

	from 10% to 90%.
			===ECU analog to digital conversion===
	A specific pulse duty factor is assigned to each
			The ECU interprets the signal generated by sensor package and converts it to a temperature value. The ECU first determines the period of the signal and then compares the signal high time to the period to determine the signal duty cycle. The period of the signal is converted to a temperature value against table '''TABGTA'''. The resultant temperature ('''TATS_W''' for bank 1 or '''TATS2_W''' for bank 2) is delivered in celsius units with possible ranges between 940C to 1035C.
	temperature (refer to diagram).

	===Substitute function and self-diagnosis===		===Substitute function and self-diagnosis===
			The ECU is capable of producing four unique fault codes for various error a sensor fault states. In the event of a sensor fault the ECU will fail-over to the working sensor to provide enrichment. In the event that both sensors have faults the ECU will fail over to an EGT limp mode where emergency enrichment
	A pulse duty factor of <1% or >99% is
			characteristic (engine speed-dependent) is utilized. The error condition must exist for three seconds ('''TVEATSS''') for the sensor to be flagged with an error code and produce one of the following DTCs. The condition will be reset after 3 seconds ('''TVEATSR''') of error free sensor operation.
	recognised as a fault.

	A fault is detected as of a certain enrichment
			====Exhaust gas temperature sensor (1 or 2) Open/Short to B+:====
	quantity.
			DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSMX'''. The stock value of '''TATSMX''' is 1034.51C. This correlates to an pulse width duty cycle of greater than 99% based on empirical data.
	If a sender fails, the charge pressure is reduced

	to a safe level and an emergency enrichment
			DTC 17861 indicates this fault for bank 1 (G235) ('''B_MXATS''') while 17865 indicates this fault for bank 2 (G236) ('''B_MXATS2''').
	characteristic (engine speed-dependent) is

	used.
			====Exhaust gas temperature sensor (1 or 2) Short to Ground:====
			DTC is produced when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is less than '''TATSMN'''. The stock value of '''TATSMN''' is 940.49C. This correlates to an pulse width duty cycle of less than 1% based on empirical data.

			DTC 17862 indicates this fault for bank 1 (G235) ('''B_MNATS''') while 17866 indicates this fault for bank 2 (G236) ('''B_MNATS2''').

			====Exhaust gas temperature sensor (1 or 2) Implausible Signal:====
			DTC is produce at engine idle when the exhaust gas temperature value ('''TATS_W''' or '''TATS2_W''') is greater than '''TATSNP''' (default value of 950.00C) while the pre-catalytic converter modeled exhaust gas temperature ('''TABGM-W''' available to measure in block 034) is less than '''TDATSO''' (default value of 500C).

			DTC 17863 indicates this fault for bank 1 (G235) ('''B_NPATS''') while 17867 indicates this fault for bank 2 (G236) ('''B_NPATS2''').

			====Exhaust gas temperature sensor (1 or 2) Signal Error:====
			DTC is produce when the signal period is outside side of the period tolerance limit defined by '''DTPATS''' (default value of 50ms).

			It is assumed DTC 17864 indicates this fault for bank 1 (G235) ('''B_SIATS''') while 17868 indicates this fault for bank 2 (G236) ('''B_SIATS2''').

Nyet: /* EGT enrich */

2012-08-09T00:12:08Z

EGT enrich

← Older revision		Revision as of 00:12, 9 August 2012
Line 12:		Line 12:

	* BTS (open loop) - when modeled EGT (block 034) reaches TABGBTS (500°C for the S4, 750°C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.		* BTS (open loop) - when modeled EGT (block 034) reaches TABGBTS (500°C for the S4, 750°C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.
	* ATR (closed loop) - when measured EGT (block 112) reaches TABGSS (980°C), ATR will add fuel via dlatr in ~~via~~ PID.		* ATR (closed loop) - when measured EGT (block 112) reaches TABGSS (980°C), ATR will add fuel via dlatr, which is generated by the ATR PID.

	==Audi documentation==		==Audi documentation==

Nyet at 00:11, 9 August 2012

2012-08-09T00:11:38Z

← Older revision		Revision as of 00:11, 9 August 2012
Line 11:		Line 11:
	There are two types of EGT enrich in ME7		There are two types of EGT enrich in ME7

	* BTS (open loop) - when modeled EGT (block 034) reaches TABGBTS (~~500C~~ for the S4, ~~750C~~ for the RS4), the requested AFR tracks lambts if it is richer than lamfa.		* BTS (open loop) - when modeled EGT (block 034) reaches TABGBTS (500°C for the S4, 750°C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.
	* ATR (closed loop) - when measured EGT (block 112) reaches TABGSS (~~980C~~), ATR will add fuel via dlatr in via PID.		* ATR (closed loop) - when measured EGT (block 112) reaches TABGSS (980°C), ATR will add fuel via dlatr in via PID.

	==Audi documentation==		==Audi documentation==

Nyet at 00:11, 9 August 2012

2012-08-09T00:11:15Z

← Older revision		Revision as of 00:11, 9 August 2012
Line 11:		Line 11:
	There are two types of EGT enrich in ME7		There are two types of EGT enrich in ME7

	* BTS (open loop) - when modeled EGT reaches TABGBTS (500C for the S4, 750C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.		* BTS (open loop) - when modeled EGT (block 034) reaches TABGBTS (500C for the S4, 750C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.
	* ATR (closed loop) - when measured EGT reaches TABGSS (980C), ATR will add fuel via dlatr in via PID.		* ATR (closed loop) - when measured EGT (block 112) reaches TABGSS (980C), ATR will add fuel via dlatr in via PID.

	==Audi documentation==		==Audi documentation==

Nyet: /* EGT enrich */

2012-08-09T00:10:36Z

EGT enrich

← Older revision		Revision as of 00:10, 9 August 2012
Line 8:		Line 8:

	==EGT enrich==		==EGT enrich==

	EGT enrich occurs at 980°C from the factory and AFAIK not many people play with it. It can be set lower, because 980 is a lot for any car. When you do actually exceed 980, you'll see some percentage values (also displayed in block 112), which shows how much extra fuel the ECU is dumping into the combustion chambers to keep the EGTs at 980 or as close to that as possible.
			There are two types of EGT enrich in ME7

			* BTS (open loop) - when modeled EGT reaches TABGBTS (500C for the S4, 750C for the RS4), the requested AFR tracks lambts if it is richer than lamfa.
			* ATR (closed loop) - when measured EGT reaches TABGSS (980C), ATR will add fuel via dlatr in via PID.

	==Audi documentation==		==Audi documentation==

Nyet at 16:14, 24 May 2007

2007-05-24T16:14:32Z

← Older revision		Revision as of 16:14, 24 May 2007
Line 1:		Line 1:
	==Exhaust gas temperature ~~control~~==		==Exhaust gas temperature measurement==

			[[VAG-COM]] blocks 034 and whatever else only display an internally calculated O2 sensor temperature, which is what most people think are real EGTs. That value may or may not have anything to do with the real EGTs or temperature at the primary O2 sensors; in fact, those temperature values are stored in 2 maps where the inputs are load and RPM.

			Block 112 is the only block where a real EGT value is displayed, and only when the actual EGTs exceed 945°C. This is only due to the design of the sensors and their electronic modules, which makes that they can only "read" 945-1035°C and that's all. So basically if all you see is 945 all the time, it means your actual EGTs never exceed 945.

			If you see block 034 EGTs hitting 750 or 800 or 850, those values have never been, are not and will never be actual EGTs. The only real EGTs are in block 112. If you want to know what they are when they're below 945, then you have to use RS6 sensors with adequate programming, so you get a range of -40 to 1100°C and then you will know what your real EGTs are.

			==EGT enrich==
			EGT enrich occurs at 980°C from the factory and AFAIK not many people play with it. It can be set lower, because 980 is a lot for any car. When you do actually exceed 980, you'll see some percentage values (also displayed in block 112), which shows how much extra fuel the ECU is dumping into the combustion chambers to keep the EGTs at 980 or as close to that as possible.

			==Audi documentation==

			===Exhaust gas temperature control===

	For turbocharged engines, the maximum		For turbocharged engines, the maximum
Line 7:		Line 20:
	To protect the exhaust gas turbocharger and		To protect the exhaust gas turbocharger and
	the exhaust manifold, the exhaust gas		the exhaust manifold, the exhaust gas
	temperature should not exceed 1000 °C for a		temperature should not exceed 1000°C for a
	lengthy period of time.		lengthy period of time.

Line 13:		Line 26:
	influence the exhaust gas temperature have		influence the exhaust gas temperature have
	tolerances, thermodynamic adaptation		tolerances, thermodynamic adaptation
	previously took place at 950 °C for safety's		previously took place at 950°C for safety's
	sake.		sake.

Line 25:		Line 38:

	The Motronic controls the exhaust gas		The Motronic controls the exhaust gas
	temperature to 980 °C by enriching the air/fuel		temperature to 980°C by enriching the air/fuel
	mixture .		mixture.

	It is therefore possible to largely dispense with		It is therefore possible to largely dispense with
Line 32:		Line 45:
	been standard practice until now.		been standard practice until now.

	The mixture is only enriched~~...~~		The mixture is only enriched
	*when necessary and		*when necessary and
	*to the extent necessary.		*to the extent necessary.
Line 45:		Line 58:
	to a high degree of accuracy.		to a high degree of accuracy.

	An accuracy of ± 5 °C is achieved in the		An accuracy of ±5°C is achieved in the
	measurement range from 950 °C to 1025 °C.		measurement range from 950°C to 1025°C.
	The exhaust gas temperature sender is located		The exhaust gas temperature sender is located
	inside the exhaust manifold upstream of the		inside the exhaust manifold upstream of the
Line 64:		Line 77:
	frequency and a variable pulse duty factor.		frequency and a variable pulse duty factor.
	The pulse duty factor is expressed as a		The pulse duty factor is expressed as a
	percentage . The measurement range extends		percentage. The measurement range extends
	from 10% to 90%.		from 10% to 90%.
	A specific pulse duty factor is assigned to each		A specific pulse duty factor is assigned to each

Pansgor: /* Exhaust gas temperature control */

2007-05-24T00:21:50Z

Exhaust gas temperature control

← Older revision		Revision as of 00:21, 24 May 2007
Line 17:		Line 17:

	This was achieved by enriching the air/fuel		This was achieved by enriching the air/fuel

	mixture.		mixture.

Nyet at 01:28, 2 September 2006

2006-09-02T01:28:22Z

@@ Line 17: / Line 17: @@
 This was achieved by enriching the air/fuel
 mixture.
@@ Line 39: / Line 40: @@
 = 1 is possible up to high load and engine
 speed ranges.