Full Mobile Diagnostic Service

If your car suffers from any of the following, you need to speak to us first.

• Poor starting
• Poor idling / stalling
• Hesitation / misfire
• Low on power
• Poor fuel economy
• Emissions failure on MOT

If a customers vehicle is suffering any of the above complaints then an appointment is made for us to visit them at their home or place of work for a complete evaluation consisting of standard preparation work, serial testing, parallel testing, formulation of results and Engineers report.

Diagnostic Approach

Step 1 – Meeting the Customer

On meeting the customer, we will sit down with them to get as much information about the fault as possible. The vehicle is road tested with the customer to see if the fault can be demonstrated.. At this point we will have either witnessed the fault first hand and / or we will have questioned the customer at great length so we fully understand all the symptoms. We appreciate that the longer we spend with the customer initially before we look at the car, the more successful we’ll be in the repair.

Step 2 - Visual Assessment

Before any test equipment is connected , a quick assessment is made under the bonnet, all vehicles have there own particular weaknesses due to poor design and all share weaknesses due to poor maintenance. Vehicle electronics have to operate in extremely harsh conditions, excessive heat, vibration and contamination are the worst enemies and all too often it’s a mechanical fault with a vehicle which can lead to a problem with a vehicle’s performance. Poor contact in wiring block connections due to water and oil leaks, dirty airflow meters due to oil contamination are all common. All these problems have to be fixed first before any electronic testing takes place.

It is quite often the case at this point we will advise the customer that some remedial mechanical work is required before further diagnosis is possible.

Step 3 - Serial Diagnostic

If all is well with step two then we next connect a serial diagnostic to the serial connector of the vehicle. Here at Autodiagnosis Limited we have a selection of serial testers collectively covering the majority of European and Asian cars. All our testers are top quality and have “Live data” capability and can be used to access other vehicle systems such as airbag, ABS, Body systems as well as Engine Management., however the most important thing is, is that all our testers are upgradeable which means as vehicle technology moves on, so do we.

At this stage the appropriate tool is used firstly to see if any fault codes exist, if there are then they noted down. We DO NOT at this point replace the component the fault code refers to as many other repairers do, this practice can work out expensive both for the repairer and the customer and is unprofessional. The relevant code is noted and the circuit it refers to is noted, this is where the Engineer has to understand how a system works and how the components integrate, you have to work out what events would lead to that code being stored. To help us further we can then access the “Live Data” from the ECU and see if it is sensible. We have a database of “Live Data” to refer to as well as experience in knowing what to expect from sensors under various conditions.

Step 4 - Parallel Testing

From the results of our serial testing we know we have one fault code logged in the ECU, we have extracted “live Data” and found some borderline values for one particular sensor, we know from speaking to the customer that the symptoms he/she described are inline with this sensor malfunctioning. It is now time for confirmation. This is done by using an Oscilloscope, we can measure a component trace using our PC Based Oscilloscope and save it as a data file for our report if we need it or we can look at it in real-time. Normally the first traces to measure are ignition, but we can look at lambda, airflow, throttle, fuel injection (pulse width) and make our evaluation. We can even go out on road test and take measurements if we need to. The advantages of measuring on the road are that the engine is working in its normal environment under load and at correct under bonnet temperatures. Using an oscilloscope on the road also allows us to capture data for illusive intermittent faults.

Step 5 - Compile Report

By now we should have Oscilloscope data that aligns with our findings from the serial tool. We can now add any digital photos if applicable and fill in our pre-formatted report. The completed report can then be printed out and given to the customer. The report consists of the customers statement of faults and our findings at each step, we then highlight as part of the report a plan to repair the vehicle, a list of actions necessary including costs of additional labour, testing and parts required. It is then up to the customer how he or she wish to proceed.