TD5 ECU A/C map

[carlosbeldia]

Good day. I've been having two problems with my TD5 when using the A/C (almost all the time): when on, it makes my consumption goes down 20%, no matter how carefully or agressive I drive. This level stays even with constant speed and with no A/C compressor installed (disconnecting compressor loom), just the A/C in on (checked by Nanocom), so it must be the ECU map.

The second is even worst: my throttle response really goes wrong when the A/C switch is on. It needs around 40% more clutch play to make the car go with the antistall, is really awfull, the same with the car going, it feells like I'm going with the throttle when using low range.

I have a MSB and am located in Colombia, so no easy way to change my ECU map. I've been thinking on cutting some wires that "reports" the A/C to the ECU, is that a good idea?

[carlosbeldia]

Another thing: this bad throttle response goes also without the compressor just with the A/C switch on.

[OffTrack]

You are looking at it the wrong way around.

The map cannot change, so it can't be a "map problem". The fault will related to the ancillaries or sensors. Switching in the A/C adds an extra load to the engine so it is an indicator that either the A/C compressor is fault or you have an issue with engine sensors that is reducing performance to a point where the A/C is causing issues.

Use your Nanocom to make a recording of the fuelling inputs, with the A/C running and without and post the resulting csv file up and someone should be able to spot whether there is amiss with the engine sensors. You need an SDCard if you have an EVO. In the Td5 Engine module, go to the Fuelling Inputs section and click on the disk icon at the bottom of the screen. You'll be prompted for a file name, and once you done this and click ok you'll get a message saying the Nanocom is recording. When you have done a decent test drive - 10 to 20 minutes is probably ok - click the disk icon to finish and save the recording. It's a good idea to do this before you switch off the ignition. The recordings are a a csv file that uses semicolons as the delimiter, so you can import into Excel or use the Td5GraphicViewer app to visualise the inputs.

Don't even think about cutting wires until you identify the cause of the problem. You might want to check the wiring harness at the various rub points, at the right front of the head around to the A/C compressor. If you have wires that are rubbed through you might be getting a short to a sensor wire that only effects the engine when the A/C switches on.

cheers
Paul

[Carlos]

Hi Carlos, I can't help with your problem. but I hope you get it sorted out, drop me a line by email.

Carlos

[carlosbeldia]

Hi Carlos, it's really great to hear about you, did you finish your trip? we have been looking a lot of Defes here in Cartagena.

All cars receives extra load from the compressor, even my friend's Cummins 6.9 Ram jumps when you hit the A/C switch. However, I feel is too high in the TD5. The map have a lot to do with this behavior, since as soon as you starts the A/C the ECU starts sending more fuel to compensate the extraload. The thing is TD5 send too much fuel. For comparison, our Hilux 2.5 gives us 38 km per gallon with no A/C and 35 with the device on, a 7,8% of difference, against my 110's 20%, for me it's really crazy, and I´ve been talking about this with two other friends who have my car in Colombia and they have these problems too.

Tomorrow I'll make the tracks you say and post them. Thanks a lot

[carlosbeldia]

You let me thinking with all this about sensors so I took the hard way: put a NNN ECU instead of my MSB and see what happen. My car is a 2001 model (MY99), the NNN is a 120, with a fuel map for an European 110 June 2002. The difference is really noticeable!!!! with the NNN and the A/C on, there is no delay in response in the throttle, no hesitation when changing gears, a complete different car, no more powerful but a lot more driveable. Which map do you think is the best for my car? some experiences in this? I don't want to run, just to use less the gearbox and transfer sticks. Thanks a lot for your help, Paul.