QuestionI have a 2003 Concorde and last week it started going in to the 2nd gear limp-in mode on a regular basis. It seems to do it only after it warms up and does it after every deceleration until it is turned off and restarted. The trouble codes are P0700-I guess a general code indicating trans trouble , P0871-OD Pressure Sw. sense circuit, and P1776- Solenoid Sw. valve latched in LR Position.
I changed the TCM relay (under the hood fuse box) and the 20amp fuse "Q" for the TCM and it didn't help at all.
My speedometer is reading normal when in the limp-in mode with no
erratic jumps in the needle.
My question is this. Could my problem still be the output speed sensor even though my speedometer is functioning normal in limp-in?
(I was hoping it would be the speed switch because of the low cost and I could do it myself.)
If not, would it most likely be the Transmission Solenoid Pressure Switch or the whole Powertrain Control Module?
I'm thinking I may be looking at a huge cost on this thing :-(
Roland, Thanks in advance for your volunteer help and all your expertise.
Robert
AnswerHi Robert,
The 0871 says that the OD pressure switch is open or closed at the wrong time relative to the gear that is in use at the time. The 1776 says the L/R solenoid itself latched when it shouldn't be.
The codes share a couple of common causes: output circuit of the transmission relay (but that you have dealt with except to verify the red wire from the relay to pin 4 of the switch/solenoid assembly (specifically the 8-wire plug on the trans). The middle pin (D) of the relay socket is the place to test for that wire's continuity to pin 4.
The tcm could also be a common cause. The pressure switches themselves could also be faulty as could there position sense wires. If you would like to check the circuits, the OD sense wire is from pin 1 of the assembly to pin 22 of the green plug at the pcm, while the wire from the LR solenoid is from pin 6 to pin 10 of the same plugs.
If those prove out, then you are left with a choice: remove,clean or replace the solenoid/switch assembly by route of the trans fluid pan removal and then the valve body removal (to which the assembly is attachec) on the underside of the transmission OR replacing the transmission controller. I have the pages from the '04 manual that show how to do the body/assembly removal if you want to try it yourself. The only cost would be the assembly in that approach. I have no experience as to which is more likely under the circumstances. Because the two codes involve different switch/solenoid gears, I lean to the 'common mode' causes rather than the possibility that both failed independently, but there is no certainty of that.
I doubt it is the speed sensor because of the normal function of the speedo, and the fact that it is not mentioned as a cause for either fault. I assume you checked the fluid level in the trans, but do so if not.
Please let me know if you want the pages as I can xerox and postal mail them to you. It cost 10 cents a side plus the stamps to get those to you which you can reimburse me for after you receive them. It appears to be a job you could do yourself from under the car (on jack stands) of course with the instructions to avoid the pitfalls.
Roland
PS Please 'rate' my answer and consider a 'nomination'. Thanks
