Communication with the EEC system
Switch off the ignition key for 90 seconds and then start the engine. If other EEC related fault codes (not CAN-time out) are present, trouble shoot these first.Turn the ignition on and off a few times. Note that there may be fault codes in the EEC system that not is detected by the EMS when fault code 100C is active.If the fault code reoccurs again and no fault code that may force EEC to shut off is present, check the wiring and clean the connectors.If the fault code still reoccurs, check that booth the EMS and the EEC gets the U15 voltage at the same time.If everything else is OK, renew the EEC in the first place and the EMS in the second place. For engines with NOx-control software, confirmation of repair requires:- Turn the ignition off, wait at least 90 s- Turn the ignition on If the fault is remedied, the DTC should now be passive.
What you'll see
No driver-visible symptom recorded.
System reaction
The EEC system will not inject any urea, which leads to higher emissions.Most of the fault codes regarding the EEC system rely on information sent by the EEC control unit. When fault code 100C is active this information will not be received by the EMS and there might be fault codes that are not generated. When fault codes are erased they might not be regenerated due to this.For engines with NOx-control software, this DTC is classed as a type D failure.
Diagnostic depth
The CAN message MSG2 ‘Urea dosing information’ (see PD 1522079) from the EEC is not received.
Communication between the EMS and the EEC has been interrupted.The EEC system shuts off when some fault codes are generated, to prevent the system from damage.If no other EEC fault codes are generated and the fault code has only been generated once, this may be due to the voltage to the EEC system has been interrupted while the EMS has been supplied with voltage. If the fault code has been generated frequently, this is probably due to a wiring or connection fault.If fault code 1638 has been generated at the same time, there is probably a fault on the EMS. If this fault code has been generated, but not fault code 1638, then there is probably a fault on the wiring.