Fault code after remap

I have a 2011 Vauxhall Insignia SRI 2.0 CDTI with 50,500 miles and a full service history. I had the ECU remapped and, after about 250 miles, it went into ‘limp-home’ mode as I was accelerating hard through the gears. Then the ‘service vehicle soon’ message illuminated on the display, so I pulled over and restarted the car and it ran OK after that.

When I got home I read the fault codes and a number came up and I cleared them all. I then drove the car for 350 miles, including towing a caravan for 110 of those miles, and no more problems occurred until today, when it went into ‘limp-home’ mode again when accelerating hard through the gears and displayed the ‘service’ message. Restarting the car cleared everything, but the only fault code now showing is ‘P0087 – fuel rail low pressure’. I think that the fault appearing after the remap is coincidental, but I can’t rule it out.

Craig Christie

As you say, the remap and the error code may not be connected, but it’s not possible to rule it out without knowing the parameters that were reset. ‘P0087’ is not one of the codes listed by Autodata as a common problem on your Insignia and may be being triggered for a number of reasons related to the fuel pressure: the fuel pump may be failing or there could be an issue with the fuel pressure regulator. Another possible cause could be a restriction in the fuel line.

As a first step, I would replace the fuel filter, checking the contents of the old filter carefully for any signs of tiny metal particles – this could be an indication of a failing fuel pump. Provided nothing untoward is found, the next step would be to check the fuel pressure regulator. With the connector plug to the regulator disconnected, using an ohmmeter between the terminals should produce a reading from the solenoid of 3.6 ohms – any variation from this reading could indicate that the solenoid is faulty.