The electrical architecture of a modern automobile is its lifeline. Contemporary vehicles are essentially electronic objects and the quality of its service in all its four main systemic compartments (power-train, body, chassis and communication protocol), like that of any electronic contraption, is dependent on its electrical fixtures: cables, relays, etc.
The ignition relay is one of the most important electronic relays found on modern vehicles. It is usually located in the fuse and relay panel beneath the bonnet, and is responsible for providing power to the vehicle’s ignition system, and some of the fuel system’s components. When the key is turned to the on position, the relay is switched on and power is directed to the vehicle’s ignition and fuel system components, notably the fuel pump and ignition coils. When the relay fails or has an issue, it can cause major problems with the operation of the vehicle. Usually a bad or failing ignition relay will produce a few symptoms that can notify the driver of a potential issue. 2000 Nissan Frontier Power Steering Pump
Car suddenly stalls while operating: One of the most common symptoms of a failed ignition relay is a car that suddenly stalls while operating. If the ignition relay shorts, burns out, or otherwise fails while the engine is operating it will cut off power to the fuel pump and ignition system. This will cause the vehicle to immediately stall due to fuel and spark being cut off. In some instances of a faulty relay, the vehicle will be able to restart once the relay cools off, only to stall out once again after the relay overheats.
Car not starting: Another symptom of a faulty ignition relay is a no power condition. If the relay fails it will cut off power to fuel pump and ignition system, which will result in a no power, and therefore no start condition. You may find that turning the key may power on the accessories, and may even crank the engine. However, the vehicle will not start due to their not being any power directed to the fuel and ignition system. Similar symptoms can also be caused by a wide variety of other issues, so a proper diagnosis is recommended in order to make certain what the issue is.
Dead battery: A dead battery is another symptom of a faulty ignition relay. If the relay has an internal short, it may keep power fed to the ignition and fuel system, even when ignition cylinder is in another position, or the key is removed. This will cause the fuel pump and ignition components to remain powered on, drawing current, at all times, which will eventually lead to a dead battery. Aside from draining the battery, this may also cause accelerated wear on the components, notably the fuel pump, due to having them powered on, but not operating.
Burned relay: In certain instances, it may be possible for the relay to overheat to the point of burning up and melting. Apart from cutting off power to the vehicle’s ignition relay and causing performance issues, a burnt relay may melt onto the fuse panel. This may make it difficult to remove, and in some instances can even lead to the replacement of the entire fuse box.
While servicing the ignition relay is not generally considered a routine maintenance, it can sometimes fail and cause major issues for the vehicle. If you suspect that your ignition relay may be having an issue, have the vehicle inspected by a professional technician.
NB: Parts of this piece is culled from the Internet.
In a failing car engine that is losing oil and being topped up with new oil, is there any benefit to servicing, especially the oil change part?
Secondly, if you say there isn’t, can I do an oil filter change at recommended intervals only and forgo the oil change? Please advise me. Nich
It depends on how bad the engine is losing oil; is it losing the engine oil through leaking or smoking? Though you said smoking, if the smoking is as a result of bad valve stem seal you can replace the seal by doing a complete valve train repair or rebuild the engine if it is as a result of worn out oil rings and cylinder walls.
Yes you can replace just the filter alone if you are using up to four litres of oil a week.
What is your take on making a choice between V6 and V4 engine cars and SUVs? I am asking because most people advise that buying a V4 engine vehicle saves cost of fuelling, while V6 cars consume fuel. Onuoha
Yes they are right. Also, you have to think of maintenance; it’s cheaper to maintain four cylinders than a V6 engine.
Please what could be the problem with my Kia Sorento 2.4L engine? The car would not rev up to 3000rpm and the check engine light is not on. On scanning the car, the following codes were reported P0222, P0076, P0652, P2110, P2106, P0123, P0453. Please advise. Anonymous
Someone must have blocked or removed the check light, because with all the codes you have, the light should be on. Below are the interpretations of the codes. But the main ones that concern the challenges you are dealing with are P0222, P2106 and P2110. Your technician should be able to use them to solve the fault.
P0076 KIA: Intake valve control solenoid circuit low bank 1
Intake valve timing control solenoid valve is activated by on/off pulse duty (ratio) signals from the engine control module.
The intake valve timing control solenoid valve changes the oil amount and direction of flow through intake valve timing control unit or stops oil flow.
The longer pulse width advances valve angle. The shorter pulse width retards valve angle. When on and off pulse widths become equal, the solenoid valve stops oil pressure flow to fix the intake valve angle at the control position.
When is the code detected?
An improper voltage is sent to the engine control module through intake valve timing control solenoid valve.
Possible causes Faulty intake valve control solenoid bank 1 Intake valve control solenoid circuit bank 1 harness is open or shorted Intake valve control solenoid circuit bank 1 circuit poor electrical connection
P0123 KIA: Throttle/pedal position sensor ‘A’ circuit high input
The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage and emits the voltage signal to the engine control module. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.
When is the code detected?
The throttle position sensor signal 1 circuit has reported a high voltage
Possible causes Faulty throttle position sensor Throttle position sensor harness is open or shorted Throttle position sensor circuit poor electrical connection
P0222 KIA: TPS/Pedal position sensor/Switch ‘B’ circuit low input
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc. The throttle position sensor responds to the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are a kind of potentiometers which transform the throttle valve position into output voltage, and emit the voltage signal to the engine control module. In addition, these sensors detect the opening and closing speed of the throttle valve and feed the voltage signals to the ECM. The ECM judges the current opening angle of the throttle valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening angle properly in response to driving condition.
When is the code detected?
An excessively low voltage from the throttle position sensor is sent to engine control module.
Possible symptoms Engine light on (or service engine soon warning light) No throttle response
Possible causes Faulty throttle position sensor Throttle position sensor harness is open or shorted Throttle position sensor poor electrical connection
P0652 KIA: Sensor reference voltage ‘B’ circuit low
The control module has two internal five-volt reference buses called five-volt reference 1 and five-volt reference 2 . Each reference bus provides 5-volt reference circuit for more than one sensor. Therefore, a fault condition on one five-volt reference circuit will affect the other five-volt reference circuits connected to the reference bus. The control module monitors the voltage on the five-volt reference buses.
When is the code detected?
The engine control module has detected the sensor five volt reference circuit voltage is lower than expected
Possible causes Faulty engine control module ECM harness is open or shorted ECM circuit poor electrical connection Shorted sensor on five volt circuit
P0453 KIA: EVAP emission system pressure sensor high input
The evaporative emission system control system pressure sensor detects pressure in the purge line. The sensor output voltage to the engine control module increases as pressure increases. The EVAP control system pressure sensor is not used to control the engine system. It is used only for on board diagnosis.
When is the code detected?
An excessively high voltage from the sensor is sent to engine control module.
1999 Toyota 4runner Power Steering Pump Possible causes Faulty evaporative emission system pressure sensor Evaporative emission system pressure sensor harness is open or shorted Evaporative emission system pressure sensor circuit poor electrical