ECM throttle body bosch low signal

autoperdu · Post by **autoperdu** » 13 Jun 2018, 12:45

Hello all,
I recently did some more pcv work on my 2005 volvo xc70, after buttoning everything back up started and ran fine, took my son to daycare the next day then car went into limp mode. Finally was able to get the car home and ran vida had recurring ECM-92CD signal too low to throttle body. So I ordered a new throttle body. When I was taking everything apart I found that I had a rag stuck in the throttle body (big doh moment

). Pulled it out and decided to button it up and see if it would run ok. It has, but I am still getting the ECM-92CD signal low after clearing the codes. Have cleared the codes through vida as well as clearing the ecu codes. So should I replace the throttle body or is it on its way out?

Many thanks in advance to any who take their time with this question.

Post by **chrism** » 13 Jun 2018, 13:46

The Bosch throttle bodies are really quite reliable, but not so much the electrical connection. I'd take a good look and make certain it's properly connected with no bent pins. That connector is a pain. I broke the retainer barbs on mine and now have to use a zip tie to keep it firmly connected.

autoperdu · Post by **autoperdu** » 14 Jun 2018, 15:08

Thanks for the reply Chrism, I only have one side snapped in myself, would it be in my best interest to replace that plug (and if so where can i get it)? And does that mean that it would be safe for me to return the throttle body I overnighted?

Post by **chrism** » 14 Jun 2018, 18:33

Since you have the new one in hand you might as well hang onto it for the moment, just in case....

Did you clean the old throttle body? I went down this same road with our 2.5 T S80. Bought a new Bosch TB needlessly. In my case the problem turned out to be the ECM connection. A local shop removed it, plugged it back in, and all was well.
I’m told you can buy the little harness from Volvo that runs from the TB to the ECM. But then again you would have to remove the ECM to change it. It’s not a big deal but it does take a special unlatching tool, which has become rather affordable since I had my problem.

Post by **mrbrian200** » 15 Jun 2018, 09:50

Does anybody know whether the low signal condition applies to the reference voltage or the sensor output?
The likely conclusion- whether you damaged the mechanical internals of the TB (for all intensive purposes plastic internal gears are a weak point IMO), or a weak electrical connection at the plug after being disturbed might hinge on what exactly this DTC refers to.