Volvo V60 - Fault tracing and misleading diagnostic codes

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Mon 11 Nov 2013 11:09
Volvo V60 - Fault tracing and misleading diagnostic codes - craig-pd130

Here's a little tale of how diagnostic codes stored in ECUs can be misleading and ambiguous when trying to trace the true cause of a fault.

Just under 3 weeks ago, I had the 'emissions warning' lamp light up in my 2011 V60 D3 when I was in the middle of a 200 mile journey. The DPF was regenerating at the time, and the regeneration stopped when the lamp lit. I checked the manual, it said the car was safe to drive. The engine wasn’t in limp mode but performance was a little reduced, so I drove the rest of the journey reasonably gently.

I called Volvo Assistance, they sent a technician who found a single EGR-related fault code (P1406) and reset it. Car was fine with performance back to normal for 150 miles and 4 days, when the emissions lamp came on again on a motorway. Drove home, called Volvo Assistance, they came and read a different EGR-related fault code (P1407).

This time, they trailered the car to the dealer. Dealer diagnosed faulty EGR valve and replaced the valve, pronouncing the fault fixed. On the 25-mile drive home from the dealer, emissions light popped up again.

Dealer collects car, investigates, fault code is again EGR related. But the EGR valve has been replaced. They find a supposedly kinked vacuum hose to the EGR valve, fit new length of hose. Dealer’s master tech takes car for 50-mile test drive, pronounces it ‘finally sorted.’

Emissions light pops up AGAIN when car is being delivered back to me, so back to the dealer it goes. This time, they work by swapping parts from a donor car. Fault is finally traced to a dodgy pressure sensor on the DPF, which has been replaced.

It just shows how diagnostic codes are just the start of a fault-finding process. The dealer throughout this has been very helpful, has never left me without a car, and has always kept me updated. But the problem certainly caused them some head-scratching.

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Mon 11 Nov 2013 11:23
Volvo V60 - Fault tracing and misleading diagnostic codes - gordonbennet

Well done to the dealer for sorting it, but 3 years down the line when this is a used and well out of warranty car the cost to find and fix something like this could run into eye watering sums.

Its for such reasons that i continue with my old MB (and no longer run a Diesel), and will continue to support my venerable make specialist indy workshops, indeed though i often look at other makes the facility of his knowledge soon puts me back on track when i get silly ideas.

Sidestepped SWMBO into a Mitsi Outlander 1 last year, its OK as a car and has some endearing features, if not looks..;), but the Mitsi dealer workshops don't instill me with confidence (hadn't a clue with a running fault which my LPG indy fixed easily) and i can see that being replaced with either another MB or a Toyota/Lexus/Subaru product next year depending on circs.

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Mon 11 Nov 2013 12:56
Volvo V60 - Fault tracing and misleading diagnostic codes - craig-pd130

Well done to the dealer for sorting it, but 3 years down the line when this is a used and well out of warranty car the cost to find and fix something like this could run into eye watering sums.

Indeed - in an idle moment at the weekend, I worked out that the dealer has already thrown something like 4 to 5 days of diagnostic time at this, not to mention parts. This already adds up to a couple of grand, easily, at main dealer rates.

Much as I love the car, I'd have to think very carefully before buying one with my own money, rather than running one as a company car.

Oddly, when I emailed the dealer with the exact circumstances in which the fault originally occurred, I did mention the DPF was regenerating at the time, and the fault was perhaps related to a DPF sensor. The dealer might have saved itself some time by checking those too, rather than following the direction indicated by the fault codes.

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