Investigating a vehicle fitted with a spark ignition engine (petrol engine), catalytic converter and air/fuel-controlled mixture preparation, and with an on-board diagnostic system (OBD system):
- Check engine adjustment data and correct if necessary.
- Run engine at approx. 3000 rpm to operating temperature.
- (oil temperature >= 80 °C). To check oil temperature.
- All electrical consumers must be switched off.
- Connect EGE tester according to manufacturer's specifications.
- In vehicles with automatic transmission, engage gear lever in "P" position.
- Activate power steering, AT and AC and check whether engine runs correctly at idle speed.
- Run the engine for at least 60 s at approx. 3000 rpm in order to ensure that the catalytic converter has reached operating temperature.
Then immediately begin the EGE measurement.
There should only be a very short time period between testing and engine warm-up, otherwise the oil temperature will not correspond to the catalytic converter temperature.
Driving Cycle, Readiness Bits
Throughout the course of the OBD-EGE test, the readiness bits are read out and documented. If there are some readiness bits which have not been set, the EGE tester attempts to read out the voltage values for the oxygen sensor. If a value which has been read out does not exist, the appropriate readiness bits must be set with the aid of the driving cycles described below. The vehicle can then pass the EGE test, as the lambda voltage was not read out for set readiness bits.
A side effect which has nothing to do with the EGE test: by using driving cycles, repairs which became necessary as a result of an activated MIL can be checked to see if they were successful.
Note. These driving cycles must be used with restraint and should not be considered to be a standard procedure.
Driving Cycle, Readiness Bits
The following diagram indicates the "EOBD readiness driving cycle" as depicted in practice (test drive) in order to check all emission-relevant diagnostics one time:
- 1. Engine start
- 2. Travel at constant speed at 50 km/h in 3rd gear (or gear position "3"), approx. 5 minutes
- 3. Idle (gear position "D"), approx. 1 minutes, after preceding overrun phase
- 4. Travel at constant speed at 70 km/h in 5th gear (or gear position "D"), approx. 5 minutes with subsequent overrun phase (overrun phase duration: approx. 18 seconds)
- 5. Idle (gear position "D"), approx. 1 minute
- 6. Travel at constant speed at 90 km/h in 5th gear (or gear position "D"), approx. 5 minutes with subsequent overrun phase (overrun phase duration: approx. 18 seconds)
- 7. Idle (gear position "D"), approx. 1 minute
- 8. For Z 14 XE, Z 16 XE, Z 16 SE and Z 16 XEP engines only: carry out actuator test for fuel tank ventilation valve (100% opening) at increased idle speed (approx. 2000 rpm) using TECH 2.
- 50 km/h, 3rd gear or gear position "3", 5 minutes
- 70 km/h, 5th gear or gear position "D", 5 minutes
- 90 km/h, 5th gear or gear position "D", 5 minutes
- Engine start
- Idle speed
- Overrun phase
Note. The diagnostic procedure depicted above is interrupted if the accelerator pedal position fluctuates greatly. The vehicle should be driven at as constant a speed as possible. In the last two overrun phases, the vehicle must be allowed to downshift in the engaged gear without braking. During the last overrun phase, there should be deceleration from at least 80 km/h to at least 60 km/h. In idle phases 3 and 5, TECH 2 can be used for a pre-test of the readiness bytes.
Exhaust Gas Measurement
Allow engine and catalytic converter to reach operating temperature.
The engine temperature and speed are read out via the diagnostic system interface in MODE 01 and transmitted to the EGE test device where the values are displayed.
Determine and record the actual values for the vehicle at increased idle speed. To do this, accelerate to the increased idle speed and hold at that speed for at least 30 seconds prior to the measurement being taken:
Increased idle speed [rpm].
Lambda value CO content in exhaust system back pipe [% vol].
Determine and record actual values for vehicle at idle speed:
The idle speed must be measured over 5 seconds and remain within the specified range (min/max) [rpm] during this time.
Functional test:check exhaust emissions-related system data from OBD system. The following system data are obtained automatically from the read out device and transmitted to the EGE test device which then automatically calculates the result:
OBD status: the OBD status indicates which OBD system has been fitted. These data are not evaluated - they are for information only.
Readiness tests: readiness tests are shown as a binary code. All supported tests must be set to "0". - Read-out of supported readiness tests, - read-out of all set readiness tests, - comparison between supported and set readiness tests.
Test on air/fuel control sensor(s) signal(s): if, during the readiness test, it was noted that not all supported readiness tests were set (binary codes = 0), the air/fuel control sensor(s) signal(s) is/are automatically read out and recorded as an additional test. Otherwise, continue with "Number of errors stored in error memory (MODE 03)".
Accelerate to test speed and hold [rpm]. The measurement is taken over 20 seconds.
Read out and record actual value(s) of the lambda control sensor(s), lambda spring sensors, voltage increase [V]
Number of errors stored in error memory: - no errors: result = 0; satisfactory (OK), - errors present: result > 0; not satisfactory (not OK)
If the number of errors does not equal zero, the read-out device automatically selects MODE 03 and the error codes of the stored errors are read out and forwarded to the EGE test device.
Evaluating and Displaying the Results of the Ege and Functional Test. Evaluation Is Done by Means of the Ege Test Unit:
- Idle speed OK/not OK
- CO and lambda at increased idle speed OK/not OK.
- Engine diagnostic system control lamp status OK/not OK.
- Selecting engine diagnostic system control lamp status OK/not OK.
- Readiness tests carried out / not carried out OK/see no 7
- If necessary, test speed OK/not OK.
- If necessary, test lambda control sensor(s) signal(s) OK/not OK.
- Number of stored errors: (no errors) OK/not OK (errors stored)
- If necessary, error codes
- Conclude test or repeat "Exhaust Emissions Test".
Reading Out OBD Data
The following data are read from the control device from the generic scan tool
- Control unit recognition
- MIL status
- Number of DTCs in mode 1
- DTCs from mode 3
- Readiness codes from mode 1
- Lambda sensor system and voltages
- Engine speed
- Coolant temperature
Compiling the Test Report (Petrol Engines)
The person responsible for the test must issue a test certificate after the exhaust gas emissions test. The test certificate must contain the following information:
- date, time, testing location, testing device type, EGE software version
- VIN
- vehicle nominal data
- vehicle actual data
- result of visual check on components and engine diagnostic system control lamp - not satisfactory (not OK), - satisfactory (OK)
- result of functional test:
- OBD status
- number of stored errors: - not satisfactory (not OK), - satisfactory (OK)
- If necessary, error codes with error text
- Readiness tests: - supported and set tests as binary code (yes: 1/0; no: 0/1), - all system tests carried out (OK) / all system tests not carried out (see result "air/fuel control sensor(s) signal(s))".
- If necessary, lambda control sensor(s) signal(s): nominal/actual comparison (OK/not OK)
- Result of EGE test nominal/actual comparison (OK/not OK)
- If necessary, deviations/notes (keyboard input only, hand-written information not permitted)
- Overall result: - EGE test passed; disc awarded as per appendix IXa - EGE test failed
- Month, year when next exhaust gas emissions test due, signature of the person responsible for the test and, in the case of vehicle workshops approved in accordance with § 47b StVZO, the inspection number.
Increased Idle Speed for Z 14 Xe (Astra-G)
Due to frequent complaints about the idling characteristics, we wish to point out that, for the above-named engine/vehicle combination, an increased idle speed of 1500 rpm may arise after starting if the engine is started from cold.
This is a fundamentally necessary measure to heat up the catalytic converter.
Testing the Regulating Circuit
See diagrams in data sheet.