Help; Trip to the mountains causing codes
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Help; Trip to the mountains causing codes
1st of all, these cars were BUILT for driving in the mountains!! 
This, however, was the 1st trip I'd made since installing my SY3500, so I was curious as to how it would be affected by the hills. On long assents at highway speeds (55-65) in overdrive, the car would feel like it would upshift as the convertor apparently "unlocked" and it would seem to start "slipping" more than usual. If I stopped at a redlight, the car would shift hard going into 2nd.
When I would stop and check, it always gave me two codes
PCM - 1870 H
IPC - 1543 H
This kept occuring over and over for the entire trip. I would reset the codes and it would do fine until I started up the next long incline.
Any ideas??
This, however, was the 1st trip I'd made since installing my SY3500, so I was curious as to how it would be affected by the hills. On long assents at highway speeds (55-65) in overdrive, the car would feel like it would upshift as the convertor apparently "unlocked" and it would seem to start "slipping" more than usual. If I stopped at a redlight, the car would shift hard going into 2nd.
When I would stop and check, it always gave me two codes
PCM - 1870 H
IPC - 1543 H
This kept occuring over and over for the entire trip. I would reset the codes and it would do fine until I started up the next long incline.
Any ideas??
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
1870 = Transmission componet slipping
ICP B1543 indicates an Oil Temperature Circuit open
I DO NOT believe that 1543 has anything to do thih the Trans code.
Check your oil temp sensor, the plug and wiring harness. Make sure the plug is on good and the wiring harness does not have any damage ie burnt chafed or broken.
I am NOT a automatic trans expert BUT it looks like the PCM is seeing too much slippage as compared to the look up tables in it's memory. Someone with AT expierence will need to chime in!
Bill
ICP B1543 indicates an Oil Temperature Circuit open
I DO NOT believe that 1543 has anything to do thih the Trans code.
Check your oil temp sensor, the plug and wiring harness. Make sure the plug is on good and the wiring harness does not have any damage ie burnt chafed or broken.
I am NOT a automatic trans expert BUT it looks like the PCM is seeing too much slippage as compared to the look up tables in it's memory. Someone with AT expierence will need to chime in!
Bill
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
Thanks Bill
I had the PCM reprogrammed after installing the TC and gears. I wonder if the programmer did not allow for the stall. Does anyone know if this can be compensated for?
Thanks
I had the PCM reprogrammed after installing the TC and gears. I wonder if the programmer did not allow for the stall. Does anyone know if this can be compensated for?
Thanks
Safety Car
Joined: Jul 2002
Posts: 3,874
Likes: 0
From: Fishing Somewhere Cold
St. Jude Donor '11-'12-'13, '15
P1870 is a common code after TC upgrades. Basically the PCM is sensing exessive slip due to the new set up. The code sets when a number of conditions have been met and your hill assent at those speeds is a perfect condition for it. The slippage noticed is an arbitrary number in the computer and the "range" of allowable slippage can be widened (with LS1 edit) to where you would really have to have a tranny problem for it to set. You can re-set this code but it will come back when the right conditions exist for it to detect what the computer feels is a tranny problem. It then increases the shifting pressure to max in an effort to save the slipping unit and this results in scary hard shifts!
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
What are your trans temps getting upto? driving in the mountains with a high stall is a good way to build up heat.. and heat is a tran's worst enemy...
Hope your running a trans cooler..
-Rick
Hope your running a trans cooler..
-Rick
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 3,011
Likes: 9
From: Dublin GA
It sounds like I just need to have the parameters reset to allow for the TC. That's definitly goods news. 
I'm not running a trans cooler since the temps generally run between 190-205 on a hot day here in the flat lands. (GA) The highest the temps got were a peak of 228 (for only about 10 mins) on the way there. I left the trans temp gage displayed and monitered it closely and never got it past 214 on the rest of the trip.
There was actually very little noticable slippage, or heat build-up, until after it would set the code each time. Then it would almost seem like it was a non-lock up converter with the way it would free rev.
Looks like a quick fix though.
Thanks
I'm not running a trans cooler since the temps generally run between 190-205 on a hot day here in the flat lands. (GA) The highest the temps got were a peak of 228 (for only about 10 mins) on the way there. I left the trans temp gage displayed and monitered it closely and never got it past 214 on the rest of the trip.
There was actually very little noticable slippage, or heat build-up, until after it would set the code each time. Then it would almost seem like it was a non-lock up converter with the way it would free rev.
Looks like a quick fix though.
Thanks
