s60 2005 t5 wiring harness throttle body

volvomadness · Post by **volvomadness** » 23 Nov 2020, 10:53

My indy Volvo mechanic who worked for Volvo for 20 years told me that the harness from the throttle body deteriorates over time.

explained that the incompatibility of the metals used are the cause.

Said in order to fix it it would have to be a re-wire at the ETM.

I have surges in the idle at start up and then it smooths out. No issues after that. But occasionally and rarely I lose power and dies. Starts right up.
No issues with coolant loss or vacuum lines. Fuel pressure sensor replace, fuel filter, breather done, exhaust vtc. No CEL.

Has any one experience with the throttle harness issues?

Madness

Post by **chrism** » 24 Nov 2020, 13:17

An indy mechanic told me that harness was often suspect to him too. Check the condition of the connection at the throttle body. The contacts can possibly get pushed back into the connector. People, including myself, often break the locking feature on the connector because it's so ornery to disconnect - a tie wrap can be used to hold it firmly connected. If nothing wrong is found there then you might try reseating the ECM into its connector. You'll need the unlatching tool anyway if you are going to replace the throttle body harness. A flaky ECM connection was the root of my throttle/dying engine problems, unfortunately that was discovered AFTER buying a new Bosch throttle body.

Have you cleaned the throttle body lately?

volvomadness · Post by **volvomadness** » 24 Nov 2020, 21:43

yes I cleaned the throttle body when i did the breather box some six months ago. Didn't break the the throttle body connector. Indy mechanic who worked for volvo for many years said the best way to fix the problem would be to rewire from the ECM.

Post by **jonesg** » 25 Nov 2020, 00:03

volvomadness wrote: ↑24 Nov 2020, 21:43 yes I cleaned the throttle body when i did the breather box some six months ago. Didn't break the the throttle body connector. Indy mechanic who worked for volvo for many years said the best way to fix the problem would be to rewire from the ECM.

I've read they often just pigtail a new connector.
Once the original plug i disturbed theres a high percentage of come backs, the wire is fine, the plug isn't.

Post by **RickHaleParker** » 25 Nov 2020, 01:44

The ETM to ECM harness is part number 31409380. You can get one for ~$40.00 .

You use a Terminal Pin Extractor tool to disconnect the old harness, removes the pins from the ECM socket.
Then install the new harness. No splicing and soldering wires together.

Goldchemist · Post by **Goldchemist** » 31 Mar 2025, 17:38

oh man I have the same issue. Just noticed two of the wires are backing their way out of the ETM connector. I also broke the locking feature after removing the darn ETM about 5 times over the years for various repairs. The connector gets brittle over time. I tried pushing the wires back in but the connector is getting so brittle I'm thinking whats the point, gotta go for a whole new kit. How many of you have just spliced the new connector on though? I'm not that eager to purchase the ECM removal tool and start messing with those wires too. Considering I can see my issue is at the pigtail, with the wires backing out. How did it work out for you volvomadness?

Goldchemist · Post by **Goldchemist** » 05 Apr 2025, 07:25

I purchased a new set of wires for the ETM from FCP euro. The colors are different but I have that figured out. Before I get too deep into the computer I'm trying to figure out where the #5 Brown wire connects in the computer. I have a very nice wiring diagram which says it connects to 31/91 ground. But is that in the ECM? I see a diagram of where 31/91 is under the hood but it is difficult to figure out where exactly that is. Plus the brown wire has a pin connector end on it, as if it plugs into the computer. Similar issue with the #6 green black. The diagram I have says it connects to 54/1B slot 14 but not sure where that is. It looks like it is a 14pin grey plug closer to the engine block but I would think all the wires would run to the ECM because they all run the length of the new wiring harness. thank you for any help.