faris_jason Posted December 20, 2007 Report Share Posted December 20, 2007 I have a 2000 Cadillac DTS. I have been having some intermittent problems with my car slamming in to gear. Well I cleaned my connector on my PCM and the issue went away for about two weeks. Well today it did it then went away and it threw a PCM 1122 code. It also did the same about a week ago. Can you guys tell me what the issue is? Link to comment Share on other sites More sharing options...
jcobz28 Posted December 20, 2007 Report Share Posted December 20, 2007 Code P1122 - Throttle Position (TP) Sensor Circuit Intermittent Low Voltage One of the things the computer looks at in order to determine how hard the transmission should shift is the TPS voltage (indicates how open the throttle is). If it sees that the throttle is all the way open (i.e. you are flooring it down the highway), then it would command a firmer shift than if it saw just 5% open (i.e. cruising 20mph down a side street). If what the sensor is reporting to the computer does not match what is actually happening, then the computer could command a hard shift during a time when you are driving the car easy, and it will feel like the shift was too hard. Someone with a FSM should chime in on the actual diagnostic procedure, but common sense tells me: 1. Check the wiring connector to the sensor. Pull it out, clean the contacts, and reseat the connector. Check for loose/chaffed wires, etc. 2. Check the sensor to see if it is within the specified values using a multi-meter. Someone with FSM will have to provide these. These sensors can go bad, but I would not replace it until you have confirmed that it is bad. Being that this is an intermittent failure, I would place my bet on it being a wiring harness / connector issue. Link to comment Share on other sites More sharing options...
faris_jason Posted December 20, 2007 Author Report Share Posted December 20, 2007 Whats is a FSM? Also can you tell me where the sensor is located? Thanks! Link to comment Share on other sites More sharing options...
Texas Jim Posted December 20, 2007 Report Share Posted December 20, 2007 FSM = Field Service Manual by HELM. The same manual the Cadillac dealer uses. E-bay can be a good place to get one. It can also be bought from HELMINC.com for 135 bucks. http://www.helminc.com/helm/welcome_retail_ahm.asp Link to comment Share on other sites More sharing options...
jcobz28 Posted December 20, 2007 Report Share Posted December 20, 2007 I found this photo of a 2000 DTS engine on ebay. The arrow points to the throttle body area, which is where the throttle position sensor should be located. It looks as if this Northstar has an electronic throttle, instead of a wire cable. I think the red arrow I drew is pointing at the electronic motor that controls the throttle. Can someone confirm this. And if so, does this setup have a separate TPS sensor? Or is it all integrated into one electronic unit? I can see how GM could get rid of the TP sensor on a motor w/ an elec. throttle. But maybe they kept it to measure actual throttle angle vs. commanded throttle angle. Someone else with more knowledge on this particular year will have to chime in. Either way, what you are looking for is in this area... Link to comment Share on other sites More sharing options...
faris_jason Posted December 20, 2007 Author Report Share Posted December 20, 2007 Man you guys are great! Thanks for your help! I will let you know what I find out in the next couple of days when I finally get some time off! Link to comment Share on other sites More sharing options...
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