Chrysler Repair: Export Neon 2001 4-speed, drb iii, roland roland

Question
Hi Kevin

Fault - no speed reading, P1698, no upshift, unstable fuel gauge reading

I appreciate you forwarding my previous P1698 question to the pool, which was in turn picked up by Roland. Roland asked about the PCM pins (P/N P05033058AG), and I can confirm that it has the standard 2x40 pin C1, C2 layout. The transmission is 41TE with TCM (P/N P05033058AG). I can't confirm the TCM pin layout as I am not next to the vehicle currently, but it's a single connector. Fused 12V to pin # 56 & pin # 30 of the TCM. Ground at pins 53 and 57 of the TCM. The bus circuit pin 4 (-) and 43 (+) of the TCM.

I would be grateful if you could relay this info please. I am interested in any diagnostic checks that can be measured with DVM or oscilloscope, to determine why I have no speed reading on a functional speed needle.

Many thanks and kind regards
MARK

Answer
Hi Mark,
First a note about the pin assignments: I haven't been able to exactly identify which other vehicle/year model wiring diagrams agree with what you wrote. As I mentionned, the domestic Neon doesn't appear to have used the 41TE in that time frame.
The test that you can do is to verify the PCI bus wire from the TCM to the PCM which I believe I gave you the color of the wire and pin assignments but can't be certain of those either. Other than that you need a DRB III to try to 'communicate' with the TCM and PCM from the diagnostic port. Based on those attempts you could conclude if the PCM or the TCM is bad.
Even those instructions are a bit opaque however and unfortunately I am working with the '02 PT cruiser transmission diagnostic procedures and the '03 Sebring powertrain diagnostic procedures manuals. The 'answer' for a lack of ability to communicate with the TCM appears to be to replace the PCM but I don't understand that.
Roland