Perodua alza car radiator fan not automatically turn on but turn on with A/C only

This is one intriguing problem that still keep me searching for the solution where the radiator fan is not automatically turn on even though the temperature already exceeds its threshold which is around 93 degrees Celsius. However even at 97 degrees Celsius the fan still not automatically turning on. Only with the Air Conditioner on the radiator fan will start to spin.

The following inspections and fix were done:

• Check the fan motor - still look firm and sturdy - in fact when the A/C is on the fan running normally.
• Replaced the Engine Coolant Temperature sensor (ECT) 
• Replaced the Radiator fan relay

Despite of the above efforts the fan still not automatically turn on when the threshold temperature is met. The search continues on. What could be really the problem?

Today 28-Aug-2022 radiator fan's motor gone kaput and replaced - tested the automatic runs again but the problem continues on. The fan will turn on only if the A/C is on.

Next Checking

10A Fuse designed as E/G inside cabin compartment (Main is the relay for Radiator fans)

ST = Start relay

MG/C = Compressor magnetic clutch relay

30A Radiator fan fuse (Engine Bay)

40A Fuse AM1 (Engine Bay)

Characteristic of Camshaft Position Sensor for Perodua Alza 2010 and how to test its genuine original feature

As described by DENSO the manufacturer of OEM parts for Toyota and Daihatsu - the camshaft position sensor is part of the engine's timing component that work along the crankshaft position sensor to detect the best timing and deliver the data to the ECU to command spark plugs firing and fuel injections as well as intake valve and exhaust valve open / close operations. It is made with delicate components consist of magnetic elements. 

Here we are not going to go through the detail but simple general real life maintenance to keep it working at the most optimum level. 

Note that since the camshaft position sensor consist of magnetic element it will contracted some tiny debris of engines' wears over time and obstruct its effectiveness to deliver data to the ECU. Therefore periodical maintenance should be perform to clean the sensors. 

• If you are cleaning it using throttle body carb cleaner make sure it is dry before installing back to the car.
• Do not use cloths or any materials that generate electrostatic charges when rubbing it onto the surface of the camshaft position sensor to avoid damaging the magnetic element inside it.

Optimum performance of camshaft position sensor is equally important as the crankshaft position sensor as they work hand in hand to keep the best timing for combustions (spark plugs, fuel injectors, oil control valve solenoid).

Where is the camshaft position sensor location on Perodua Alza car?

It's located on the right hand side of the engine (from front view) below the MAP sensor. Sometimes it is hidden by the engines wiring harness intersections. The bolt spanner size is 10mm. 

How to determine the originality of camshaft sensor whether it is genuine or fake (replica, imitation, knock off)

1. Perodua Alza 2010 uses camshaft position sensor with product code 90919-05024 made by DENSO
2. The camshaft position sensor only has two wires
3. On the connector has written word "JAPAN" (protruding) and "ND" (engraved) then DENSO (protruding) see picture below.
4. On the tip surface has a ring round shallow indent - this where metal debris usually stick when it's get dirty. - See picture below
5. Has engraved TOYOTA word and part numbers on the camshaft position sensor
6. Resistance = 2100 Ohms 2.1 kOhms
7. Sensor Type = Inductive Sensor
8. Voltage = 12V
9. Fitting Depth = 30mm or 3cm
10. Number of pins = 2

Other OEM camshaft position sensors manufacturer have resistance between 2.1 kOhm ~ 2.2 kOhms

 

Manifold Absolute Pressure (MAP Sensor) Characteristic

• Manifold Absolute Pressure normal readings at Idle (750 RPM) = 4.6 ~ 5.2 psi and around 890 ~ 900 RPM should reads around 5.5 ~ 6.4 psi.
• Low MAP sensor readings indicates low loads therefore the ECU / ECM will command injectors to deliver less fuel  vice versa higher MAP sensor readings means more loads thus more fuels injected for combustions,
• High MAP sensor readings at idle could be caused by 
• vacuum leaks
• bad throttle body butterfly mechanism
• throttle cable adjusted to much cause the throttle butterfly to open slightly allowing more air to enter the intake manifold
• The result of higher readings of manifold pressure will cause poor fuel economy.

Small air bubbles inside the radiator cooling system but big impact on idle

A couple of months ago just sending Alza car for water pump replace at the Perodua service center. Since then the radiator temperature tend to increase significantly when the car is on idle for quite long. It could go up to 97 degree Celsius very close to the overheat threshold. However when it gets moving on the road the temperature goes down to normal within the range of 83 ~ 85 degree Celsius. It has been going on like that since then and sometimes need to turn off the engine when parking to avoid the radiator temperature going high.

Thought it could be the water pump - but before going into the trouble of taking it off for inspections I went for the basic maintenance first. So after getting the spill proof funnel from Shopee tried to burp the air bubble which could be the problem. So here is the video of it.

 

After removing the air bubbles from the cooling system - so it was true that those little air present in the cooling system can affect the car coolant temperature significantly. Now the highest temperature on idle is around 85 degree Celsius and rarely go up to 87 which is still within the normal temperature threshold level.

So the lesson learnt from in this case is the present of air bubble inside the radiator (cooling system) have big impact to the coolant temperature. It's best to get them out before any unwanted occur.

Understanding the relationship of fuel consumptions and engine loads and oxygen sensor

I've done quite an extensive research about car's fuel consumptions - but little did I know that it is actually quite simple. Back to the basic principle of all engine's which consume fuels based on the load it has to carry which means more loads more fuels. Just like electric motors the heavier the motors the more Amperage it use to spin the motors. Let's focus specifically on car's fuel consumptions.

1. Car running without air conditioner save more fuels - although it is not the most desirable but it is true that if you are running car's without the A/C on it will save lot's of fuels. This is tested on OBD2 ecu scanner where fuel consumptions increase significantly when air conditioner is turned on. The technical principle behind this is very simple as the A/C system is turned the compressor magnetic clutch automatically engage to add more loads to the engine. As a result more fuels are needed to run the A/C compressor unit. Apart from that radiator fan and cabin blower fan also turned on giving signal to the ECU to command the alternator to work harder to stabilize the current which also increase fuel consumptions.

2. Aging cars - as the pulleys, bearings, and driveshaft, power steering, transmission, and internal engine parts worn out over time. It will add more frictions which mean loads and leads to more fuel consumptions to turns those parts. The components potential list of components.

• Alternator pulley and bearing
• Water pump pulley
• Crankshaft pulley
• Power steering pump
• Tensioner pulley
• Serpentine belt
• Driveshaft bearing
• Power steering

3. Over mileage used of engine oil and transmission fluids will loose its lubrications effectiveness on the engine and gearbox which leads to more loads. 

4. Bad car braking system - such as seized brake pads and brake drums could also increase loads which require more fuels to burn.

5. More passengers or loads inside the car obviously increase more engine loads.

6. Climbing uphill also increase engine loads.

7. Cruising car on the road save more fuels based on the average reading vs on Idle. As the car cruising on the road its load is lighter than having to move from initial positions. Just like a simple electric motors require more current to kick at the initial start and less current as it already spinning.

8. Changing gears too frequently also increase more loads example in automatic transmissions changing the gear will consume more fuels on every shift either from Parking to Drive or Parking to Neutral or Vice versa. This is because of torque changes at every gear shift add loads at the initial engagement.

Oxygen Sensor (O2 Sensor).

Perhaps we are too naïve thinking that the oxygen sensor of the car contribute to significant fuel consumptions. Theoretically yes maybe but it's main purpose only capture combustion activity (oxygen) and send the data to the ECU to make adjustment from the basic fuel consumptions which based on the engine's loads. 

The O2 sensor does not adjust to the point that where the car can't run due to heavy loads for the sake of fuel economy. Which means fuel consumptions of a car always benchmark by the loads and then adjusted by the oxygen sensor. So in my opinion the O2 sensor play little roles in car's fuel consumption. 

However if the O2 sensor happen to be faulty - the car will display check engine light or might not turn on at all. But a worn out O2 sensor will still work only that providing the ECU with inconsistent data but the car will be able to run and carry the loads that it is capable of handling.