AG Electronics

021 939 9359

Weekdays: 8am-6pm

079 146 1402

The following information is not to be used a self diagnostics of a vehicle. If you're experiencing issues with your vehicle please contact us to arrange an appointment for a proper diagnostics on vehicle.

- AG Electronics (PTY) LTD


Body Control Module

A Body Control controls the non-engine systems on your vehicle.

It controls:

  • Central locking
  • Windows
  • Wipers
  • Exterior and interior lighting
  • Immobilizer.

It can also cause battery drain, a non starting car, a problem with the in car entertainment system and will usually cause the check engine light to come on.

Powertrain Control Module

Commonly reffered to as an engine control unit, computer box, or engine controller. It controls the injection of the fuel and, in petrol engines, the timing of the spark to ignite it. It determines the position of the engine’s internals using a Crankshaft Position Sensor so that the injectors and ignition system are activated at the exact time.  



  • Ambient Temperature sensor
  • Coolant temperature
  • Airflow
  • Accelerator position
  • Knock sensor
  • Oxygen sensor
  • Cam position sensor
  • Wheel speed sensor
  • Fuel Injection
  • Ignition Timing
  • Variable Timing
  • Turbo boost
  • Wastegate
  • Blow off valve
  • EVAP
  • Cylinder Deactivation

My car is not starting...

Can you turn the key in the ignition?
1. The steering is locked by the ignition. Turning the wheel right and left whie gently jiggling the keys in the ignition.
2. The lock mechansm might be worn out. Try to use a spare key.



There's no lights on the instrument panel?
It could be a dead battery, (no current flowing to instrument panel), no connection to the cluster, or a bad ignition switch. Switch on your headlights, if they are working then your battery has enough voltage.



When you turn the ignition on, does a key shaped light flash on te instrument panel?
The car's system might not recognise the key. Try a spare key



Does the check engine light come on the instrument panel?
It usually indicates that there's no power to the engine control unit, but can also refer to a break in connection or no power to the PCM due to another component causing a loss of power.



Turn the ignition to start position. What Happens?

A) Nothing happens (No crank, click and engine won't start)
The starter motor might not be functional.
This is most commonly caused by a dead battery.
Other faulty components which causes this issue include: The ignition switch, starter motor solenoid, neutral saftey switch, ECU, BCM.


B) There is a click
This can be caused by a weak or faulty battery, or bad terminals (Usually caused by corroded battery terminals)



C) The engine cranks vey slowly



D) The engine cranks for a short while then just clicks.



Basic car check:
* State of the battery
* Automatic vehicles: If the  car does not start in the "park' gear, does it start in another gear?
* Is there enough fuel?
* Is the security or key shaped light flashing on the instrument cluster?



How to check your battery
-> Turn the windscreen wipers on. If they're moving much slower, then the battery probably has a low voltage.


Transmission Control Units

Transmission control units (TCU) is a type of automotive Electronic control unit that is used to control electronic automatic transmissions.



The most common signs of a bad transmission control module include:

  • You have difficulty downshifting when you’re slowing down, coming to a stop, or manually trying to downshift.
  • You have difficulty upshifting when you’re trying to accelerate or manually trying to upshift, which can cause a delay in acceleration.
  • You have difficulty shifting or cannot shift out of neutral.
  • Your transmission shifts to neutral or to another gear on its own.
  • There’s a delay when you try to shift from one gear to another.