79 series codes

[Moorabinda]

Hi all,

I've owned my 79 series for the last 7 years since new - always performed as expected - until a couple of nights ago when Check Engine light came on and it went into limp mode.

Basic scanner revealed the following codes:

P0045- turbo boost control solenoid

P0100 - Mass air flow circuit
P0488 - EGR throttle control circuit
P062E - Fuel injector driver
P20CD - Exhaust aftertreatment fuel injector
P213B - EGR Throttle control circuit
P245C - EGR cooler bypass control circuit

Vehicle is in very good condition, and codes only came up upon starting i.e. not whilst driving.

Any idea what's going on? I've checked all fuses and they're all ok.

Cheers, Nick

 

[Petespendthrift]

I don’t know 70 series at all but since no one else has answered and I do know 200 series well, so if it was me, I would do the following.

If it was a non-persistant fault and can’t be replicated it will be hard to track down. But if it is persistant and so still present, it then has to be an electrical issue and the components involved are all connected to the ECU. First make sure the battery/alternator is good as any low voltage or high voltage could affect the ECU. Make sure the battery terminals are not corroded. Then I would start by looking carefully at the wiring coming from the main plug into the ECU. Possible suspects could be rodent damage from chewing that electrical harness, water getting into the harness/plugs/ECU, oil contamination (even tiny amounts get drawn by capillary action inside the insulation of wires and can travel a surprisingly long distance and make it into the ECU - you might see oil somewhere else on the harness and plugs that has allowed that). Then look at the ECU itself. Unplug it and take it out of the firewall to see if there is any sign of water, oil or corrosion. Look for water ingress inside the cabin as well, footwells, under the dash etc. If you have a sunroof or have had a new windscreen fitted then the risk of water into the cabin is increased.

Make sure the battery is disconnected before unplugging anything.

If you find nothing, then it could be worth looking at the fuse box and relay box more carefully, including the components that are hidden (there are items underneath the top panel with all the fuses that could have also have got wet or failed). There are also numerous relays inside the top section of the fuse box that might be worth testing - by swapping them for other ones of the same type to see if the fault changes. When you check the blade fuses, be aware that you may not always be able to see that one has been burned as the breaks can be small so a multimeter might help check continuity. Beyond that it might need a professional who can test the ECU for faults on a test rig.