15 Jun 2024
The voice of the independent garage sector

Process, process and more process

People ask me what made the difference this year when I went from being a Top Technician finalist to a Top Technician winner, and my answer is my process. I have worked hard since last year’s final, refining my process, and learning from my mistakes and it thankfully paid off this year. This article highlights the importance of a great process not only in Top Technician, but also in everyday working life, and how a fault, which at first may seem overwhelming, can be simplified and confidently fixed.

The week after winning Top Technician, a 2016 Ford Ranger was booked in for me to have a look at from another garage. The garage’s complaint was that multiple warning lights were present on the dashboard along with multiple warning messages, the power steering was heavy and the indicators and windscreen washers didn’t work from their respective stalks.

As with every job, the first step of my process is to interview the customer and gather as much information as possible. When I questioned the garage owner, he said they had just completed fitting a galvanised chassis. He explained that the vehicle had been fully stripped and rebuilt in the process, and since the rebuild, warning lights, messages and other complaints were now present. The next step was to confirm the fault. Upon starting the vehicle to bring it into my bay, the complaint was verified. The engine management, traction control, anti-lock brake and airbag warning lights were illuminated along with multiple different messages, one of which was a steering assist malfunction warning (see fig. 1).

Complete picture
I then carried out a global scan of the vehicle to get a complete picture of what faults were present and also to see what modules were or were not talking to the scan tool (see fig. 2).

Straight away we could see that multiple modules could not communicate with the power steering control module (PSCM) and restraints control module (RCM). It was also noted that there was a communication issue between the body control module (BCM) and the steering column control module (SCCM).

 As the instrument panel cluster (IPC) communicated and reported stored fault codes, I knew it was more than likely a historic fault code which wasn’t related to the issues present. Attempting to communicate directly to the PSCM, SCCM and RCM with the scan tool all returned a ‘no communication’ message, so we knew we were dealing with hard faults that were currently present. Following my process, I decided the next step was to do some research on this particular vehicle using Ford ETIS which is Fords online information portal. This allows me to access wiring diagrams, connector locations and anything and everything related to the vehicle in question. As many a clever man has said, “if you don’t know how it works how can you fix it?”

 Thinking of possible causes, I decided to study the wiring for the PSCM and RCM, how the indicators and windscreen washers work and a network topology to allow me to see how all the modules communicate to each other and the diagnostic scan tool.
 It was found that the steering column module controlled the indicators and washers and sent the message to the BCM to activate them. As the SCCM wasn’t communicating it now made perfect sense why those functions were not operating. Next, I found that all three modules worked on the high speed can data bus and all were powered by fuses. All the related information and diagrams were printed out and taken to the vehicle so that a test plan could be drawn up and executed.

Plans within plans
Before writing up my plan, I made a visual inspection of wiring under the bonnet and underneath the vehicle. Having had a major overhaul, something as simple as there being a connector left unplugged could cause some of if not all the faults present with this vehicle. Everything looked ok, so I laid out my wiring diagrams and proceeded to write a plan. My plan was to test the fuse for each of the modules to see if it gave me direction, then if all was ok I would look at the communication wiring and how the modules at fault linked into each other and the rest of the vehicle.

All three fuses tested fine so it was onto seeing if there was a common link. Looking through the topology, I found a page which had the PSCM and RCM joined by two connectors. This is where technical information is a must, as dealing with a fault like this it can be very easy to dive in full speed. I don’t want to go straight to a module, for example the RCM, and remove half the interior of the vehicle to find all is ok there and have to spend time reassembling everything! I speak from experience here, and I am sure some of you reading can relate to this.

Diagnostic direction
ETIS showed one connector inside the nearside front wheel arch and the other in the location of the bulkhead of the vehicle. This meant I could test the network without removing anything, saving time and gaining diagnostic direction. I inspected visually to see which of the two connectors was the easiest to access and it was the connector in the nearside wheel arch. Visually the connector looked correct and looked to be correctly latched.  However, I decided to double check and upon squeezing the two sides together and audible click was heard meaning the connector was open (see fig. 3).

 I then decided to scan the vehicle again to see if this had made any change and every module now communicated and it was also noted the dashboard warning lights had disappeared. I cleared all the faults codes in the vehicle. None returned, and the dashboard now had no messages or warning lights illuminated. The final checks proved the steering assistance now worked correctly and the indicators and washers operated completing the fix.

In the end then a fairly simple fix once it was established how the system worked and where everything was located but without the correct information and a well polished process this job could have taken a very different, and perhaps longer, turn.