Lotus 2004 Eleven Service Notes page 282

Lotus Service Notes
JJ.17 - LOTUS SCANNER TOOL 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 the diagnostic codes is available only by using the 'Lotus Scan' tool connected to the DLC (see
JG.15). The 'Lotus Scan' is a hand held electronic scanner tool with an LCD display panel which is able to
display any stored trouble codes and sensor readings as well as allowing manual operation of actuators.
The facilities available include:
- View fault codes/wheel speeds/valve activities
- Clear fault codes
- Generate valve/motor activities
- Read EEPROM contents
- Read ECU identification
Important Notes
- Whenever the Lotus Scan tool is connected, the ABS tell tale is lit and the anti-lock function is inopera-
tive.
- Never connect or disconnect the DLC to/from the control unit with the ignition switched on.
- Before charging or quickcharging, disconnect the battery from the vehicle electrical system.
- 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.
Section JJ
Page 37