Lotus Evora, Service Notes, Page: 204 / 370

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Lotus Service Notes Section JL
JL.16 - ‘LOTUS TECHCENTRE’ CHECKING PROCEDURES
1. Trouble Codes
When the ABS controller detects a fault in the system, the following events occur;
i) The ABS tell tale is lit;
ii) The anti-lock system is switched out;
iii) A trouble code is stored in the non volatile random access memory i.e. memory which is retained when
the power supply is interrupted, or the battery disconnected.
Trouble codes may be either Condition Latched, or Ignition Latched:
Condition Latched;
With this type of fault, which is generally low or high voltage, the ABS tell tale will light, and
the anti-lock system switch out, until such time as conditions return to normal, at which point the light will be
extinguished, and the anti-lock be reinstated. The trouble code will be stored only whilst the fault is present.
Ignition Latched; This type of fault, of which are most categories, will cause the tell tale to be lit and the anti-
lock to be inhibited until such time as the fault is no longer detected at the moment of a subsequent switching
on of the ignition. At this point, the lamp will be extinguished, and the ABS restored, but the trouble code will
be retained in the memory for the next 20 drive cycles i.e. ignition switched on and a minimum road speed of
5 mph attained.
Access to diagnostic codes is available by using the Lotus TechCentre laptop PC connected to the Diag-
nostic Link Connector (DLC - see JL.14). This tool allows the display of any stored trouble codes and sensor
readings as well as allowing manual operation of actuators.
The facilities available include:
- Viewing fault codes/wheel speeds/valve activities.
- Clearing fault codes.
- Generating valve/motor activities.
- Reading EEPROM contents.
- Reading ECM identification.
- Updating ECM calibration.
Important Notes
- Whenever the Lotus TechCentre tool is connected, the ABS tell tale is lit and the anti-lock function is in-
operative.
- Never connect or disconnect the DLC to/from diagnostic equipment with the ignition switched on.
- Unless using a trickle 'battery conditioner' type charger, disconnect the vehicle battery before charging or
boost charging.
- Never disconnect the battery from the vehicle electrical system with the engine running.
- Never use a quick-charger for starting.
- Take care when touching energised parts of the ignition system.
- ECMs must be removed prior to welding operations, or subjecting to oven temperatures above 80°C.
- When voltage testing, use only a high-resistance type meter.
- During test steps which involve the connection of contacts from harness plugs or control units with ground
or battery voltage (+12V), exercise great care as incorrect contact can cause permanent damage to the
ECM internal circuits.
- When measuring resistance from ground bearing wires to vehicle ground, the nominal value of ‘less than
2 ohms’ sometimes cannot be achieved. In this case, disconnect the negative (ground) post of the battery
and measure the resistance to the vehicle earth lead.
- Always erase trouble codes from any control unit after a test is done.