[BornAgain040707]

From a warmed up vehicle, after being at a stop sign, my gear indicators ALL lit up, speedometer quit functioning, and the vehicle appears to be stuck in about 2nd gear.

A friend changed the speed sensors without making a difference. Last week we took the O'Riley diagnostic and came up with error code P1698 reading: "PCM Fault: No CCD Message from TCM".

I am about to have a neutral safety switch put in, which O'Riley stated was the problem.....but others are warning me that the 29.00 part is NOT the problem, based on the gear indicator lights all being lit up at once....

ANY HISTORY?

 

[andyg]

That switch is NOT the problem. Since you have a 4th gen, you shouldn't have a separate fuse for the TCM, but you have to inspect all wiring to the trans.

The weird thing is, on the 4th gen, the TCM is integrated in the PCM too and they should be able to talk to eachother. But wiring and fuses would be my first thing to check.

 

[Jeepman]

Sounds like the output speed sensor is defective, or not connected, based on your being in limp mode and your speedometer not working. A disconnected output speed sensor can do that to my Van. I know because I experimented with doing just that in tracking down a cruise control problem.
There can be quite a strain on the wires to that sensor, perhaps one is broken. I actually spliced additional pieces of wire in mine to relieve the pulling. Since you replaced the sensor, then likely the wire needs looking at. Then again, sometimes new parts are defective.
As to what the codes imply, I don't know without doing some research. Sounds like wiring needs to be checked out in any event.

 

[andyg]

A speed sensor problem would not cause a no ccd code. The CCD is (from my minimal knowledge of computer things) the network how the computers talk to things like the instrument cluster. Something broke a wire in the ccd system. A service manual is probably required to know which wires are the ones to look at, but from looking at allpar the good thing is that the network is only 2 wires.

 

[RIP]

Yup, agree with Andyg except on one very minor point. Your 4th generation van (01-07) uses a PCI data bus. Serves the same function as the CCD data bus, it's just faster.

Anytime a data bus codes pops up the instrument cluster solder joint issue gets talked about, at least on 3rd gen vans. It's a comparative rarity on 4th gen vans but it does happen. So, here comes my writers cramp again. As Andyg said, the PCI data bus is used by all the control modules for communications. Multiple simultanious signals from various sources travel over just two wires. The internal module circuits look for low voltage pulses from these wires to turn various functions on or off. Because of the low voltages involved it doesn't take much to screw up the entire bus circuit. A miniscule bit of corrosion or ... a tiny crack in a soldered connection can create multiple problems in all or part of the data bus. One common problem point is the solder connections affixing the harness connector to the instrument cluster circuit board. Another is the HVAC control panel connector. It can overheat and melt to some degree, opening the data bus circuit. I read of one fix involving the harness under the battery tray. Another was as simple as reseating the TCM/PCM connectors. As I said, data bus problems can be found anywhere on the bus. These are a few of the more common problem areas.

Why is your PRNDL indication involved? The Transmission Range Sensor (TRS) in the transmission is the signal source. When you shift, its internal switches send signals to the TCM. This "data" is sent over the PCI data bus to the Front Control Module (FCM). It then heads to the instrument cluster and on to the PRNDL indication.

j

 

[Jeepman]

Did some searching using "no ccd message from tcm" and found lots of information for the Generation 3 such as this informative trouble shooting process for a 1998, but nothing for the Generation 4. :wall: