EGR code is back.
Apparently a loose connection according to the code.
Can reset it but it keeps coming back.
Been to the auto elec, as put a new genuine EGR on and same error.
They have tested plugs and wires and think it is the Computer. They reckon to remove and get computer looked at.
Has anyone encountered this?
Regards
KA
2011 RC Colorado 3L TD Check Engine Light
Re: 2011 RC Colorado 3L TD Check Engine Light
KA74
Because of the possible age/KMs of the vehicle, have you considered the EGR cooler may be choked up with carbon and causing restriction of the EGR exhaust gas flow and the ECU is seeing insufficient flow and creating a code. Yes, resettable but still present under certain conditions and the threshold is passed.
Has the auto elec actually tested the ECU plug end wiring for reliable continuity to the EGR stepper motor plug? I think not.
Has the auto elec actually removed the plugs and inspected the pins and connector socket ends with a high power magnification and LED light source so any anomaly can be detected. Recently I had a Corolla fuel pump give trouble. The problem was the socket sleeves in the connector were much larger than the fuel pump pin cross section. Mostly touched but sometimes NOT. Simple but difficult to find unless you think outside the box. It is easy to recommend ECU investigation if their competence in problem solving isn't up to the required standard. If your engine wiring loom has sagged and moves around a bit it may have fractured and intermittently stops touching. Any loose wiring may be the area to examine after unwrapping the loom section.
Remember, any slight corrosion between wire and crimped socket pins may be the cause and may require removing each socket pin one at a time so integrity can be confirmed. A "GOOD" auto elecahould be able to achieve that.
PS. in my opinion. If the ECU is faulty it will remain that way and not change in and out of function. It simply follows the instructions supplied or not supplied to it.
Because of the possible age/KMs of the vehicle, have you considered the EGR cooler may be choked up with carbon and causing restriction of the EGR exhaust gas flow and the ECU is seeing insufficient flow and creating a code. Yes, resettable but still present under certain conditions and the threshold is passed.
Has the auto elec actually tested the ECU plug end wiring for reliable continuity to the EGR stepper motor plug? I think not.
Has the auto elec actually removed the plugs and inspected the pins and connector socket ends with a high power magnification and LED light source so any anomaly can be detected. Recently I had a Corolla fuel pump give trouble. The problem was the socket sleeves in the connector were much larger than the fuel pump pin cross section. Mostly touched but sometimes NOT. Simple but difficult to find unless you think outside the box. It is easy to recommend ECU investigation if their competence in problem solving isn't up to the required standard. If your engine wiring loom has sagged and moves around a bit it may have fractured and intermittently stops touching. Any loose wiring may be the area to examine after unwrapping the loom section.
Remember, any slight corrosion between wire and crimped socket pins may be the cause and may require removing each socket pin one at a time so integrity can be confirmed. A "GOOD" auto elecahould be able to achieve that.
PS. in my opinion. If the ECU is faulty it will remain that way and not change in and out of function. It simply follows the instructions supplied or not supplied to it.
Re: 2011 RC Colorado 3L TD Check Engine Light
Thanks Mydmax,
The autoelec had the car today for a few hours.
Cannot recall the code error number P0004? The connection one.
He checked the pins on the main plug to the egr and closed the pins to ensure they were connecting.
The next stage is to check continuity of all the wires from the EGR plug to wherever they go and then check the ECU.
The vehicle actually runs fine, normal fuel consumption and power feels same. Just the light on and (maybe my imagination) a slightly rougher idle.
Autoelec doesn't want to do it before Christmas as too busy and worried if the ECU is an issue it will take a few weeks to get back and there is the christmas closedown.
Frustrating, but they appear to be going down the path you suggested of checking all the wires for continuity, but at the next visit.
Will update when i know more, sounds like late January now.
Regards
KA
The autoelec had the car today for a few hours.
Cannot recall the code error number P0004? The connection one.
He checked the pins on the main plug to the egr and closed the pins to ensure they were connecting.
The next stage is to check continuity of all the wires from the EGR plug to wherever they go and then check the ECU.
The vehicle actually runs fine, normal fuel consumption and power feels same. Just the light on and (maybe my imagination) a slightly rougher idle.
Autoelec doesn't want to do it before Christmas as too busy and worried if the ECU is an issue it will take a few weeks to get back and there is the christmas closedown.
Frustrating, but they appear to be going down the path you suggested of checking all the wires for continuity, but at the next visit.
Will update when i know more, sounds like late January now.
Regards
KA
Re: 2011 RC Colorado 3L TD Check Engine Light
For what it's worth , there is no fault code P0004 listed in the Haynes manual for any model D-Max.
Re: 2011 RC Colorado 3L TD Check Engine Light
KA
Has the EGR valve body been removed and cleaned while off the engine? The problem may be carbon buildup in the valve and not allowing sufficient EGR flow to be detected as normal. Don't assume it is solely an electrical problem.
What is happening can be electrical fault and wrong signal or could be be wrong flow of exhaust gas causing ECU to generate a code.
Has the EGR valve body been removed and cleaned while off the engine? The problem may be carbon buildup in the valve and not allowing sufficient EGR flow to be detected as normal. Don't assume it is solely an electrical problem.
What is happening can be electrical fault and wrong signal or could be be wrong flow of exhaust gas causing ECU to generate a code.
Re: 2011 RC Colorado 3L TD Check Engine Light
I used to get low EGR gas flow codes when I was pulling a boat up a ramp and had an EGR restrictor plate plate fitted but they were easily cancelled by OBD2 Autodoctor and didn't recur until the next time I retrieved the boat. This led me to remove the plate and fit a catch can.
Re: 2011 RC Colorado 3L TD Check Engine Light
EGR Engine Light Update
The Autoelec has had the car and looked at it finally after the Christmas rush and break and then backlog of other cars.
No evidence of electrical problems were found, other than they did replace the EGR cooler solenoid as it was faulty (which didn't fix the issue).
Now have new EGR Valve unit and EGR Cooler Solenoid
The do reckon there is a boost leak. They can see soot near the turbo/manifold/egr cooler and recommend no further electrical investigation until this is dealt with.
They think the loss of boost is the problem and it is confusing the engine management computer. They can reset the light for a while and it is off at idle, they reckon when the engine revs as soon as they hear a leak, the engine light comes back on.
So we (the autoelec said this now a mechanical issue) now need to investigate the EGR cooler, the exhaust manifold and the turbo and find where the leak is that is making the mess.
The autoelec thinks this will fix it, just doesn't know where the leak is.
Will update once we find further information.
The Autoelec has had the car and looked at it finally after the Christmas rush and break and then backlog of other cars.
No evidence of electrical problems were found, other than they did replace the EGR cooler solenoid as it was faulty (which didn't fix the issue).
Now have new EGR Valve unit and EGR Cooler Solenoid
The do reckon there is a boost leak. They can see soot near the turbo/manifold/egr cooler and recommend no further electrical investigation until this is dealt with.
They think the loss of boost is the problem and it is confusing the engine management computer. They can reset the light for a while and it is off at idle, they reckon when the engine revs as soon as they hear a leak, the engine light comes back on.
So we (the autoelec said this now a mechanical issue) now need to investigate the EGR cooler, the exhaust manifold and the turbo and find where the leak is that is making the mess.
The autoelec thinks this will fix it, just doesn't know where the leak is.
Will update once we find further information.
Re: 2011 RC Colorado 3L TD Check Engine Light
KA74
If the auto elec can hear an exhaust leak AND there is a EGR flow code problem, the issue may be the EGR cooler is blocked and that is the same as an EGR valve or EGR stepper motor fault. If you run the engine and use a small dia hose to your ear and the other end moved about to trace any hissing/gas escaping noise you might find the location of the leak near the EGR cooler.
The EGR cooler has two hoses to it for coolant flow and an exhaust gas entry near front upper end of manifold. The EGR cooler is also bolted to the side of the head at the rear side of the cylinder head and it passes exhaust gas through a rear of the cylinder head port to the LHS where the EGR is bolted on.
Maybe have the EGR cooler removed and cleaned out IF restricted with exhaust crud and /or leaking. Some draining of coolant will be required to get the level below the manifold.
The EGR cooler has two stainless steel gaskets, a 3 bolt one and a rear two bolt one to seal hot exhaust flow. Can be reused if sprayed with copper gasket spray. Use the small hose to listen to both sites beforehand to check if leaking. Anyone can do it!
It would have to have a fair old leak of exhaust gas to cause a detection by the ECU that flows are not balanced. My money is on the EGR cooler is blocked/restricted.
I recently had all the EGR cooler, turbo, dump pipe, manifold and inner engine side cover containing the oil cooler, all situated under the manifold and am familiar with it all. Mine had a coolant leak at front of inner side cover.
If the auto elec can hear an exhaust leak AND there is a EGR flow code problem, the issue may be the EGR cooler is blocked and that is the same as an EGR valve or EGR stepper motor fault. If you run the engine and use a small dia hose to your ear and the other end moved about to trace any hissing/gas escaping noise you might find the location of the leak near the EGR cooler.
The EGR cooler has two hoses to it for coolant flow and an exhaust gas entry near front upper end of manifold. The EGR cooler is also bolted to the side of the head at the rear side of the cylinder head and it passes exhaust gas through a rear of the cylinder head port to the LHS where the EGR is bolted on.
Maybe have the EGR cooler removed and cleaned out IF restricted with exhaust crud and /or leaking. Some draining of coolant will be required to get the level below the manifold.
The EGR cooler has two stainless steel gaskets, a 3 bolt one and a rear two bolt one to seal hot exhaust flow. Can be reused if sprayed with copper gasket spray. Use the small hose to listen to both sites beforehand to check if leaking. Anyone can do it!
It would have to have a fair old leak of exhaust gas to cause a detection by the ECU that flows are not balanced. My money is on the EGR cooler is blocked/restricted.
I recently had all the EGR cooler, turbo, dump pipe, manifold and inner engine side cover containing the oil cooler, all situated under the manifold and am familiar with it all. Mine had a coolant leak at front of inner side cover.
Re: 2011 RC Colorado 3L TD Check Engine Light
A boost leak will be in the inlet system.I'd have a look at the ducting between the turbocharger discharge and the inlet manifold. On my supercharged MB a small leak in this area can make huge differences to the boost pressure. There's usually a fan shaped area of cleaned metal leading from the leak.
Re: 2011 RC Colorado 3L TD Check Engine Light
Thanks Mydmax and Mike C,
Today the servicing mechanic went to another mechanic who has 'had this issue before' and they checked all again (not quite sure what or why), now the claim is the new genuine EGR valve is faulty and should replace under warranty, and because it has been so long they may charge to replace (sounds like a lot crap to me, this shouldn't be my problem).
The engine light can be turned off and vehicle runs for a while and drives well without coming back on. When the car has cooled and is at idle there is no light on starting, but light returns immediately when throttle applied.
Seems to not be an electrical issue(?).
Allegedly no leaks, but they haven't removed the EGR Cooler to check. Yet the Autoelec reckons there is a leak?
This is getting rather frustrating and expensive for no result.
Sounds like I will need to check the Turbo / EGR cooler for leaks myself as per your advice.
Am getting a bit sick of their attitude that the car has k's on it and should expect this. Should still be repairable, seems to be a knowledge gap somewhere.
Will tell the mechanic they can replace the EGR valve at their cost, I am not paying for it. Gonna be annoying if the old EGR valve is ok still.
Thanks again for your advice, will check the EGR coooler and advise.
Regards,
KA
Today the servicing mechanic went to another mechanic who has 'had this issue before' and they checked all again (not quite sure what or why), now the claim is the new genuine EGR valve is faulty and should replace under warranty, and because it has been so long they may charge to replace (sounds like a lot crap to me, this shouldn't be my problem).
The engine light can be turned off and vehicle runs for a while and drives well without coming back on. When the car has cooled and is at idle there is no light on starting, but light returns immediately when throttle applied.
Seems to not be an electrical issue(?).
Allegedly no leaks, but they haven't removed the EGR Cooler to check. Yet the Autoelec reckons there is a leak?
This is getting rather frustrating and expensive for no result.
Sounds like I will need to check the Turbo / EGR cooler for leaks myself as per your advice.
Am getting a bit sick of their attitude that the car has k's on it and should expect this. Should still be repairable, seems to be a knowledge gap somewhere.
Will tell the mechanic they can replace the EGR valve at their cost, I am not paying for it. Gonna be annoying if the old EGR valve is ok still.
Thanks again for your advice, will check the EGR coooler and advise.
Regards,
KA