AL4 Vehicle Speed Sensor

Since someone asked about the location of the vehicle speed sensor, it is part of the AL4 transmission and located near the drive shaft. I don't have pictures of my own, so here's some from the internet.

The easiest way to gain access to it is from under the car. Removal is easy, just remove the bolt and slowly pull the sensor out.

AL4 Transmission Temperature Sensor

The instructions for replacing the AL4 transmission temperature sensor is at http://www.peugeot206cc.co.uk/repair-206/206/info/gb/b2cg83k3.htm

Throttle Body

I had nothing better to do, so I decided to open the throttle body. The engine has not been idling smoothly, so it was a good idea to open up the throttle body to check.

After opening it up, I found a layer of sticky carbon buildup around the idle air control (IAC) valve, the air bypass passage and the throttle. No wonder the engine was not idling smoothly. Anyway, a good clean with a toothbrush, cloth and some petrol helped remove most of the carbon.

The throttle body; throttle at the bottom, air bypass passage at the top, idle air control valve at the top right and throttle position sensor (TPS) at the bottom right.

The idle air control valve is cleaned. No more carbon on the valve.

Carbon removed from the air bypass passage.

A peek inside the air intake.

AL4 Output Speed Sensor

AL4 Transmission Breather Hose

Many people have debated on the existence of the AL4 transmission breather hose. To end the debate, here's a photo of it. It is located under the battery and looks L-shaped.

Peugeot 206 MAP Sensor

I've noticed a bit of engine oil in the air intake into the throttle body. I guessed some of oil could have fouled the MAP sensor (Manifold Absolute Pressure Sensor), perhaps causing the strange gear change problem when the engine is started from cold in the early morning.

I'm also wondering whether the blended engine oil could have caused this. Yes, in the effort to make use leftover engine oil, I've mixed several brands together. The bad thing about this now is that there's a lot of oil in the air hose from the engine to the throttle body, which should not be the case. Lesson learned, mixing engine oils is bad.

After taking out the MAP sensor, sure enough it was soaked in black gooey engine oil. Did a bit of cleaning and now it looks cleaner.

The location of the MAP sensor.

The Bosch MAP sensor.

Removed much of the oil from around the yellow blob, which I guess is the sensor.

Cleaning the sensor with contact cleaner results in better throttle response and more stable idling.

Here's other people cleaning their MAP sensor.

Dodge Cummins MAP cleaning:
http://mopar.mopar1973man.com/cummins/2ndgen24v/map-sensor/map-sensor.htm

Jeep Liberty MAP cleaning:
http://liberty.eurekaboy.com/mapsensor.htm