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Driving a trip

Driving a trip

Fault diagnosis described in the service manual always ends with a final check.

The final check includes a driving cycle that is specific for each type of rectified fault.

The driving cycle ensures that On-Board Diagnostic II is performed for the function in question.

Any remaining fault will subsequently be revealed on DTC readout.

After an individual fault has been rectified, a check is made in this way to confirm that the fault really has been rectified.

A trip entails driving in such a way that all components and functions embraced by On- Board Diagnostic II are monitored.

After a very extensive repair involving a large number of emission-related components or functions, such as when the power train has been removed, a trip may well be warranted. Any faults can be revealed afterwards by requesting a DTC readout.

When a trip has been made, all conditions for On-Board Diagnostic II have been fulfilled one by one in the right order.

The time it takes to complete a trip will mainly depend on the following factors:


• traffic conditions

• driving style

• engine management system version

• any faults detected

• climate (affects A/C and radiator fan engagement, which may disturb a certain diagnosis). Since the various possible combinations of the above factors are infinite in number, the time it takes to complete a trip may vary widely. The following example of a trip is therefore only valid if the following conditions are fulfilled:

• choice of traffic conditions according to driving profile

• driving according to driving profile

• Trionic M96-

• A/C disengaged and radiator fan engaged continuously for a certain time

• only 1 fault can be detected with certainty.



1. Clear any diagnostic trouble codes and unplug the temperature sensor connector from the ICE so that the radiator fan will run continuously during the trip.


2. Diagnosis of the majority of components and functions except: front heated oxygen sensor, evaporative emission system and three way catalytic converter.



• Driving in town traffic for such a length of time that vehicle speed exceeds 0 km/h for a total of 10 minutes.

• braking at least 6 times from >40 km/h to 0 km/h

• Diagnosis of the front heated oxygen sensor and evaporative emission system

• Stop the car, run the engine at idling speed and proceed as follows:

• select Neutral (or Park) and apply the handbrake

• turn off the A/C (ACC: select ECON)

• do nothing to affect engine load (power steering, electrical equipment, etc.).

• depress the accelerator a second or two and then run the engine at idling speed for 30 seconds. Repeat three times

• Diagnosis of three way catalytic converter:

• driving with steady throttle at 40-90 km/h for 4 minutes

• select a gear so that engine speed is 2000-3000 rpm

• throttle position changes should be avoided, so as level a road as possible should be chosen

• Final check

• Check whether any diagnostic trouble code has been generated and take remedial action as necessary

• Connect the temperature sensor to the ICE

• Clear the diagnostic trouble code for the ICE temperature sensor