Pre-heating system — description and testing (Peugeot Partner I)

Table of contents: Description of the design 🠇 Examination 🠇

Description of the design

1. Each swirl chamber contains a glow plug (sometimes called a glow plug), screwed into the cylinder head. Glow plugs are energized before and during cold engine starting.

2. The supply of electrical power to the glow plugs is controlled by the pre-heating system control unit. With the exception of later 1.9L (WJY) and all 2.0L engines, the control unit uses signals received from the coolant temperature sensor and the accelerator switch on the high pressure fuel pump. On later 1.9L (WJY) and all 2.0L engines, the control unit is controlled by the electronic fuel injection control unit (see chapter 4B).

3. On some models, glow plugs also serve as "post-glow." When this function is active, the glow plugs remain lit for a short time after the engine is started. After the starter is turned off, the glow plugs begin to operate in the "post-heating" mode, which has a specified duration. Post-glow is only implemented when the engine is cold (coolant temperature below 60°C on 1.8 and 1.9 L engines and below 20°C on 2.0 L engines) and if the engine is subject to load, power supply to the glow plugs will be interrupted.

4. The driver is informed about the operation of the heating phase by a control lamp located on the front panel. The lamp goes out when the operation of the heating function already allows the engine to start. Power continues to flow to the glow plugs for a few seconds after the lamp goes out. If no attempt is made to start the engine, the timer cuts off the electrical power to the glow plugs. This prevents battery discharge and glow plug burnout.

Examination

1.8L and 1.9L engines

5. If the system is faulty, testing is generally performed by substituting known good components, but certain preliminary checks can be performed as described below.

6. If applicable, release the clips on the right side and top surface of the engine cover, then carefully remove the cover, being careful not to lose the rubber mounts.

7. Connect a 12 V voltmeter or test lamp between the glow plug power cord and the "ground" point (metal element of the engine or body). Check for short circuit between power supply circuit and engine/body.

8. Ask an assistant to turn on the ignition and check what voltage is applied to the glow plugs. Note the amount of time the test lamp remains on and the total amount of time the power is applied before the system shuts down. Turn off the ignition.

9. At a coolant temperature of 20°C, the standard indicator lamp duration should be 5 or 6 seconds. After the lamp goes out, another 10 seconds of power supply should follow. The duration of the indicator lamp burning increases at lower temperatures and decreases at higher temperatures..

10. If there is no power supply at all, then the control unit or the corresponding wiring is faulty.

11. To locate the faulty glow plug, on models with a 1.9L D9B engine, remove the air distribution housing. If necessary, also remove the air intake duct and disconnect the vent hose from the oil filler pipe. For more information, please contact chapter 4B. Disconnect the main power wire and the connecting wire or busbar from the upper glow plug sections. Be careful not to drop the nuts and washers.

12. To check the continuity of the electrical circuit between each glow plug terminal and ground, use a continuity tester or a 12V test lamp connected to the positive battery terminal. The resistance of a working glow plug is very low (less than 1 ohm). Therefore, if the test lamp does not light or the continuity tester shows high resistance, the glow plug is faulty.

13. If you have an ammeter, you can check the current in each glow plug. After the initial surge of 15 to 20 A, the current to each spark plug should be 12 A. Any spark plug that reads more or less than this value is likely faulty.

14. As a final check, the glow plugs can be removed and inspected as described in the next paragraph.

2.0L engines

15. The system can be tested as described in paragraphs 7-14. However, testing will be difficult due to the temperatures at which the pre-heating system operates; when the coolant temperature is above 0°C, heating is not actually required. The approximate heating time is as follows:

Coolant Temperature/Preheat Duration