Intake manifold heater (IMH) (Peugeot Eurovans 806)

intake manifold heater (IMH) (see illustration 11.34) designed to heat the throttle body so that it does not freeze in cold weather. When the engine is running, the heater is on all the time. PTC Heater (RTS) allows the current to quickly heat the inductor body during the warm-up process. As the heater heats up, the resistance increases and the current decreases. Since the supply voltage is generated from the second contact of the fuel injection relay (FI), so the voltage is only available when the engine is running.

Throttle body heater voltage values

Terminal numbers

See illustrations 11.2, 11.3, 11.4, 11.5, 11.6

Intake manifold heater resistance

Terminals	Resistance
1 and 2	Not specified (check for conductivity)

Intake manifold heater type

Positive temperature coefficient (RTS).

Express test

Start the engine from a cold state and touch the area around the throttle body. If the heater is running, this area should become very hot in a very short time. Be careful not to burn your fingers!

Intake manifold heater checks

1. Let the engine run at idle speed.

2. Connect the negative lead of the voltmeter to ground.

3. Connect the positive voltmeter lead to the heater power connector.

4. The voltmeter should show the nominal voltage of the battery.

No supply voltage

5. Check the output voltage from the relay

6. Check for continuity in wires between relay and heater

7. If battery voltage is present but the heater is not using it

8. Check heater resistance

9. Check heater grounding