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Ford C-Max: Sudden loss of power
A 13 year old FORD C-MAX becomes stubborn and repeatedly refuses to obey the pressure on the accelerator pedal. The cause of the loss of performance is only found on the fourth visit to the workshop.
Ford C-Max: Sudden loss of power
The Ford C-Max, built in 2005, only had 127,000 kilometers on the clock when its 1.6 liter turbodiesel engine started to malfunction. “The engine temporarily loses power while driving and the engine fault light comes on,” explains the owner during the following workshop visit and requests repairs. Additional information: The error disappears after switching off the ignition, but unfortunately only temporarily. Now a real workshop odyssey begins for the C-Max, at the end of which it is sent home with the EGR valve, turbocharger and particle filter including probe replaced - but unfortunately with the same error as before. The owner finally turns to Hannes Deimel's workshop in Bad Blumau, Eastern Styria, which specializes in diesel engines. The company has been a Bosch Car Service Partner since 2004 and has also been certified as a Bosch Diesel Center since 2007. Hannes Deimel is convinced of the benefits of digitalization and uses, among other things, the “experience-based repair database”, or EBR for short, provided by Bosch. This way he can finally find out the true cause of the error and solve the mysterious case.
▶ First, the error memory is read out, whereby two error codes appear: “Glow time control interruption/ground/positive circuit” and “Exhaust gas recirculation system function restricted”.
▶ Deimel's employee starts troubleshooting in the direction of exhaust gas recirculation and checks various actual values such as air mass. Conclusion: Everything is within the target range.
▶ The automotive technician notices that the EGR valve and turbocharger look new and, after consulting with the customer, learns that these components, as well as the particle filter with probe, had already been replaced by the previous workshop - without success.
▶ During an extended test drive, the customer's perception is confirmed - loss of engine power and the error lamp lighting up.
▶ Since the employee cannot see any connection with the drop in performance while driving, he uses the database provided by the Bosch diagnostic software ESI under the title “Online Error”
▶ Immediately after entering the error code, the crucial message appears: There is a defect in at least one glow plug.
▶ The automotive technician examines the glow plugs and finds that they are all defective. He replaces it, deletes the error and carries out a test drive: The error message and the loss of power no longer occur - case solved.
WRONG TRACK
Originally, glow plugs in diesel engines were primarily used as a cold starting aid. The metal or ceramic pins, which are electrically heated to over 1,000 degrees, now also play an important role in exhaust gas aftertreatment in modern diesel engines. The glow plug continues to heat for some time after starting to reduce the amount of unburned hydrocarbons in the exhaust gas. This explains why defective glow plugs can lead to the error codes “exhaust gas recirculation” and in the OBD “emissions-related errors in the system not completed”. In the current case, the automotive technicians got off on the wrong track and unnecessarily replaced several intact components in the vehicle. If they had had access to the EBR database, they would have saved the customer a lot of money because replacing the glow plugs was comparatively much cheaper.