Engine Tier-3 710655- Ch 1 page 32 Fault codes Troubleshooting using flash codes for the ECU control unit • The diagnostics lamp for the control unit always comes on for a second when the system is powered up. • As soon as a fault is detected by the control unit, a fault code is stored in the EEPROM and the diagnostics lamp for the control unit (the left-hand lamp on the instrument panel) lights up. • The diagnostics lamp will remain permanently lit for as long as a fault is active. Even if the lamp has gone off and the fault is no longer active, the code can generally be read off in accordance with the instruction below.
• The diagnostics lamp for the control unit stays on during engine shutdown for as long as the control unit and coordinator are powered up. Checking: • Fault symptoms • Conditions in which the fault occurs • How often the fault occurs • If the diagnostics lamp lit up when the fault occurred • If the diagnostics lamp went out by itself when the fault ceased • If the fault codes have been erased SHOP MANUAL MT26-31 - 06.2005