harrydunn Posted June 2, 2003 Report Posted June 2, 2003 The car is back from the shop and has been diagnosed with the usual torque converter shudder problem that is so common. Tech said it was probably getting ready to throw the p1870 code. Was told about the kit from Sonnax to fix the problem and was curious as to some of your opinions who have used the kit. What were the results? What did it cost you to have it done? Thanks. Quote
GPRACER Posted June 2, 2003 Report Posted June 2, 2003 P 1870 is a pretty complex code and can be used to diagnose many tranny problems, and a lot needs to happen for the code to set. Circuit Description The Powertrain Control Module (PCM) monitors the Torque Converter Clutch (TCC) slip by calculating the difference between the engine speed and the transmission output shaft speed. When the PCM detects an excessive amount of slip when the TCC is engaged, then DTC P1870 sets. DTC P1870 is a type A DTC. Conditions for Setting the DTC No TP DTCs P0122 or P0123 No VSS DTC P0502 No 1-2 solenoid performance DTC P0751 No 1-2 solenoid electrical DTC P0753 No 2-3 solenoid performance DTC P0756 No 2-3 solenoid electrical DTC P0758 No TCC PWM solenoid electrical DTC P1860 No TCC enable solenoid electrical DTC P1864 The engine speed is greater than 500 RPM for 5 seconds Not in fuel shut off The throttle angle is 9.5-35% The transmission is not in first gear The transmission gear range is D4 The transmission fluid temperature is 20-130°C (68-266°F) The engine torque is 70-230 N·m (50-170 lb ft) The MAP is 0-105 kPa (0-15 psi) The TCC is commanded ON and at maximum apply for 5 seconds The TCC slip is greater than 200 RPM for 8 seconds The above conditions must occur three times with the TCC commanded OFF between each occurrence I'd be interested to see what the kit you refer to is and what it does as well. If I knew what it was I'm sure some of the tranny specialists at work would be able to give us a good description of how to fix your problem. The part that got me was that the problem must occur at a greater change than 200 rpm for 8 seconds AND must occur 3 times in order for the code to set. that means that the converter must slip for a total of 24 seconds for this code to set. Mine would only slip for 1-2 seconds, a very short shudder. Before you get into the transmission, try the missfire thing, I exhausted it with my car but it still turned out to be the problem. AND at least 5 other mechanics said that it was the transmission. Get your self a known good coil, 2 new plugs and 2 known good wires. replace one coil pack at a time and the corresponding 2 plugs and wires. if no change, move on to the next 2 and then the last 2, this was how I eventually figured mine out. Worth a try and I can probably find you a coil to use for testing if you can't get one really cheap. Quote
harrydunn Posted June 3, 2003 Author Report Posted June 3, 2003 Wow, that is a lot to go wrong to set the code. Regarding the misfire, I've replaced all plugs and plug wires with AC Delco parts and two GM mechanics have said the coil pack is fine. One of them even had a scanner on the car while I took him for a ride. When it started bucking uphill in overdrive he said he was not "reading" a misfire. Do you think it is still worth looking into? If so, could you give me a complete run-down on how to change/test them? I'm fairly mechanically savvy if I have instructions for what I'm doing so I think I could handle it. It's got to be easier than chaning the three rear spark plugs! That was a killer! Quote
harrydunn Posted June 3, 2003 Author Report Posted June 3, 2003 Wow, that is a lot to go wrong to set the code. Regarding the misfire, I've replaced all plugs and plug wires with AC Delco parts and two GM mechanics have said the coil pack is fine. One of them even had a scanner on the car while I took him for a ride. When it started bucking uphill in overdrive he said he was not "reading" a misfire. Do you think it is still worth looking into? If so, could you give me a complete run-down on how to change/test them? I'm fairly mechanically savvy if I have instructions for what I'm doing so I think I could handle it. It's got to be easier than chaning the three rear spark plugs! That was a killer! Quote
harrydunn Posted June 3, 2003 Author Report Posted June 3, 2003 Sorry about that. Lot of traffic tonight on my ISP. Quote
GPRACER Posted June 4, 2003 Report Posted June 4, 2003 If the GM tech was using a TechII scanner and he said there were no misfires, than there were no missfires. With that scanner and your OBDII diagnostic system you can monitor each cylinder for missfies. If missfires were your problem, than the tech would have picked it up. I spoke to a couple of out trans specialists at work, and a p1870 usually means a physical slip, not a solenoid problem. Possibly the TCC, or the 3-4 clutch bands, or even the 1-2 clutch bands. Quote
harrydunn Posted June 4, 2003 Author Report Posted June 4, 2003 Yah, he was very confident that it is the torque converter clutch acting up. He said he has seen it on many occasions. Of course, he couldn't do anything about it because the warranty won't cover it and it's no throwing a code--yet. I'll keep you posted. Will probably have it looked at after the warranty's up soon. Thanks for your input. Quote
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