- engine coolant temperature;
- intake air temperature.
After the glow plug indicator goes out, if the starter is not engaged, the glow plugs remain energized for an additional 13 seconds (no more at -25°С).
Block diagram of preheating:
1158 - block preheating;
1160 — glow plugs;
1320 - engine control computer.
Post-heating is activated after the end of the pre-heating phase. The glow plugs are energized without power limitation. The speed of activation of candles depends on the temperature of the coolant, atmospheric pressure (air density), as well as the amount of injected fuel.
The glow plugs have a total voltage of 11 volts.
Candle length: 118.4±0.8 mm.
The manufacturer's mark is stamped on the housing in the area «A».
Post-heating is switched off in the following cases:
- the post-heating time limit has been exceeded;
- the ideal value of the coolant temperature has been reached;
- the value of the intake air temperature is erroneous;
- load and engine speed are too high.
Post-heating is used to reduce hydrocarbon and nitrous oxide emissions and to increase engine load in order to reach optimum catalytic converter and/or particulate filter temperatures as quickly as possible (if it is installed).
Parameters that can interrupt post-heating:
- engine temperature should not be lower than 65°С;
- cyclic fuel supply above 30 mm3 (1200 to 1500 rpm);
- cyclic fuel supply above 10 mm3 (2500 rpm);
- cyclic fuel supply above 5 mm3 (330 rpm);
- the engine crankshaft speed is more than 3500 rpm;
- battery voltage is below 7.5V.
Block of pre-start-post-heating
Peugeot 207 uses new pre-heating unit with black eight-pin electrical connector (instead of the black nine-pin electrical connector). The following figure shows the layout of the pre-heating unit «NAGARES».
Assignment of the connector pins of the block of pre-start-post-heating
Contact No. 1: power supply for spark plugs and preheating of cylinder No. 3.
Pin #2: Power supply for the heater plug for cylinder #1.
Contact No. 3: diagnostics of the preheating and afterheating control unit.
Pin #4: 12 volts DC.
Contact #5: «weight».
Pin No. 6: power supply for the heater plug of cylinder No. 4.
Pin no. 7: power supply for the heater plug of cylinder no. 2.
Pin No. 8: Diesel injection ECU input.
Preheating
Post-heating
Location of pre-post heating unit:
3 - spark plugs;
4 - wiring harness;
5 - control unit for pre- and post-heating;
6 - cylinder block.