friendly_jacek Posted March 2, 2006 Share Posted March 2, 2006 Here is the deal. 2 years ago the car (2000 legacy) would act up (bad, delayed, and harsh AT shifting) from time to time. MPG was worse than usual. Took it to the dealer several times and they "could not replicate the problem." Then it threw a CEL and flashing AT temp light with codes 122 and 31 for ECU and TCM, respectively. This pointed to TPS. I took it in for I thought was warranty work (the car had 4 years and like 40000 miles at the time). They replaced TPS and produced a $360 bill. I double checked and indeed the TPS did not seem to be covered by neither drivetrain nor emission warranty. I was pissed even more when the car started doing same thing AFTER the part was swapped. Clearly, intermitten connection problem. I took it back and was not a happy customer. Somehow they fixed it again. Fast forward almost 2 years and some problem again. I checked the TPS, works flawlessly. I started troubleshooting by the book (FSM), the whole 4 pages of checking grounds and connections, I'm not finished yet but good so far. How do I procede when the connections check out? BTW, there are no other electrical/ground problems other than the intermitten TPS problem. Do I have a recurse with the dealer and their botched "repair"? Quote Link to comment Share on other sites More sharing options...
Legacy777 Posted March 2, 2006 Share Posted March 2, 2006 Personally, I don't think your TPS was ever the problem in the first place. Too many mechanics are just parts changers any more, and don't actually troubleshoot. Do like your doing...check all the wiring. The problem may be temperature dependent as well....if so, it's going to be tough trying to track down which wire is the actual culprit. Quote Link to comment Share on other sites More sharing options...
blitz Posted March 2, 2006 Share Posted March 2, 2006 I'm with Josh. Also note that the problem is intermittant rather than constant. Important why? Well, when doing your diagnostics, you need to be looking for an intermittant problem instead of a constant one. Checking a sensor is a 5-minute job, but tracing the integrity of the rest of the harness involves starting at one end, and working systematically toward the other - don't jump around ...that won't give you any useful information. Quote Link to comment Share on other sites More sharing options...
WAWalker Posted March 2, 2006 Share Posted March 2, 2006 Have seen this before. That TPS does not have sloted holes for adjustment, but when you loosen the screws it can be moved a little bit. With DVOM connected to TPS signal wire, KOEO, closed throttle voltage should be ~ .5V. Loosen screws on sensor, move sensor to obtain lowest voltage reading, tighten screws. Also check throttle cable adjustment, and inside of throttle body for any build up that could keep the throttle plate from closeing all the way. Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted March 2, 2006 Author Share Posted March 2, 2006 Have seen this before. That TPS does not have sloted holes for adjustment, but when you loosen the screws it can be moved a little bit. With DVOM connected to TPS signal wire, KOEO, closed throttle voltage should be ~ .5V. Loosen screws on sensor, move sensor to obtain lowest voltage reading, tighten screws. Also check throttle cable adjustment, and inside of throttle body for any build up that could keep the throttle plate from closeing all the way. Thanks a lot! Didn't think of this. Quote Link to comment Share on other sites More sharing options...
rugbyben Posted March 2, 2006 Share Posted March 2, 2006 I'm sorry but has anyone seen Office Space? "Let me tell you a little somthing about TPS Reports......" Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted March 2, 2006 Author Share Posted March 2, 2006 I'm sorry but has anyone seen Office Space? "Let me tell you a little somthing about TPS Reports......" You mean like: Dom Portwood: Hello, Peter. What's happening? We need to talk about your TPS reports. Peter Gibbons: Yeah. The coversheet. I know, I know. Uh, Bill talked to me about it. Dom Portwood: Yeah. Uh, did you get that memo? Peter Gibbons: Yeah. I got the memo. And I understand the policy. The problem is, I just forgot this one time. And I've already taken care of it so it's not even a problem anymore. Dom Portwood: Yeah. It's just that we're putting new coversheets on all the TPS reports *before* they go out now. So if you could just remember to do that from now on, that'd be great. All right! No, I didn't see Office Space! Quote Link to comment Share on other sites More sharing options...
rugbyben Posted March 2, 2006 Share Posted March 2, 2006 You mean like:Dom Portwood: Hello, Peter. What's happening? We need to talk about your TPS reports. Peter Gibbons: Yeah. The coversheet. I know, I know. Uh, Bill talked to me about it. Dom Portwood: Yeah. Uh, did you get that memo? Peter Gibbons: Yeah. I got the memo. And I understand the policy. The problem is, I just forgot this one time. And I've already taken care of it so it's not even a problem anymore. Dom Portwood: Yeah. It's just that we're putting new coversheets on all the TPS reports *before* they go out now. So if you could just remember to do that from now on, that'd be great. All right! No, I didn't see Office Space! Sweet.... Drifting off topic here for a sec.... did you see the TV version where he actually explains to "The Bobs" what TPS reports actually are? I dont recall the quote but basically they are useless.... that leads in to the joke where they ask Lumberg how much time he spends on TPS reports a week... Aad before you ask....Yes i am a HUGE Movie Dork! Quote Link to comment Share on other sites More sharing options...
WAWalker Posted March 3, 2006 Share Posted March 3, 2006 Love that movie:grin: Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted March 6, 2006 Author Share Posted March 6, 2006 I'm with Josh. Also note that the problem is intermittant rather than constant. Important why? Well, when doing your diagnostics, you need to be looking for an intermittant problem instead of a constant one. Checking a sensor is a 5-minute job, but tracing the integrity of the rest of the harness involves starting at one end, and working systematically toward the other - don't jump around ...that won't give you any useful information. Blitz, how do I check for intemittant electrical problem? I finished the "static" testing and all TPS conections (and isolation from ground) to TCM and ECM checked out OK. BTW, it took me forever to find the ECM, it was cleverly hidden. The WAWalker suggestion was good but did not help. According to the FSM troubleshooting I should replace TCM, but I consider that long shot and last resort. Quote Link to comment Share on other sites More sharing options...
WAWalker Posted March 6, 2006 Share Posted March 6, 2006 Wiggle test. Do you have a scan tool? Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted March 6, 2006 Author Share Posted March 6, 2006 Wiggle test. Do you have a scan tool? Well, the wiggling of the wires near TPS does nothing. I'm not sure how to wiggle the wireing between the engine and the TCU/ECU. Yes, I have an OBD2 interface. Quote Link to comment Share on other sites More sharing options...
WAWalker Posted March 6, 2006 Share Posted March 6, 2006 Unfortunately when the problem is intermittent, you will not be able to pin point it with out duplicating it. Wiring failures are very uncommon, so if wiggling the wiring harness at or near the connectors does nothing then that should rule out a bad connection inside the harness connectors. Be sure that the large connectors on the RH side of the transmission bell houseing are pluged in all the way. Next I would try to reproduce the problem while driveing with a scan tool that can record all the sensor data in order to capture data at the time of the failure. Quote Link to comment Share on other sites More sharing options...
blitz Posted March 6, 2006 Share Posted March 6, 2006 Blitz, how do I check for intemittant electrical problem? I finished the "static" testing and all TPS conections (and isolation from ground) to TCM and ECM checked out OK. Hook up a DVM and drive around with it. The TPS is supposed to provide the ECU & TCM both with a solid analog DC voltage signal that varies with throttle opening, but doesn't drop below .45V or go above 4.5V. Start by having it hooked up to the TPS output (right at the TPS connector). When the CEL comes on, check the meter. If the reading is bouncing, then you have a problem upstream of where your meter is tapped into. If the reading's not fluctuating, then the problem is downstream (toward the ECU / TCM). Move on to the next appropriate connector and repeat the test there. Rinse, lather, repeat. This is signal tracing ...it's time consuming and cumbersome, but either you get your mind around the technique, or you pay someone else to do it. First make a little drawing (of the 3 wires) on paper, then follow along it logically. **** *S****! Quote Link to comment Share on other sites More sharing options...
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