Operation; Cold Start - Mbe900 And Mbe4000 - Detroit Diesel DDEC VI Application And Installation

5.2 COLD START – MBE900 AND MBE4000
The MCM has optional support for an electric Grid Heater for use as a cold start aid. The Grid
Heater element is operated by a high current relay. If the heater is enabled, the MCM will turn
the Grid Heater relay on and off as required.
5.2.1

OPERATION

The cold start procedure has several states. The cold start states and outputs during a successful
engine start are listed in Table 5-2 and described in the following sections.
State
Initialization
Preheating
Ready for Engine Start
Engine Starting
Post-heating
Cooling Off
OFF
Table 5-2 Cold Start States and Outputs
NOTE:
If ignition switch off is detected, the MCM remains in the current state for 5 seconds.
If the ignition is switched on again, cold start proceeds. Otherwise the MCM changes
to the cooling off state.
Initialization
When ignition is switched on and engine speed is 0 rpm, the MCM determines preheating time,
post-heating time and the coolant switch off temperature. The preheating time is shortened
when the cold start device is not cold.
A preheating time of 0 indicates, that no cold start is needed for the following engine start. If the
preheating time is greater than 0, the MCM enters the preheating state.
Preheating State
Engine cranking detection during preheating will stop the Preheating process and the canceling of
the Cold Start function. The Cold Start function will also be canceled when low battery voltage
codes are active.
When the Preheat time has elapsed, the Wait to Start lamp will go off and the engine is ready to
start.
All information subject to change without notice. (Rev. 01/07)
7SA827 0701 Copyright © 2007 DETROIT DIESEL CORPORATION
DDEC VI ELECTRONIC CONTROLS APPLICATION AND INSTALLATION
Wait to Start Lamp
Off
On
Off
Off
Off
Off
Off
Grid Heater
Grid Heater Relay
Off
On - Preheat Time
Off
Off
On - Post Heat Time
Off
Off
5-5