My 96 Disco I with 130k miles on it is in the shop right now getting fixed. It had a slew of problems i tried to remedy myself, but had no success with. I dropped it off at my local rover dealer so i could finally resolve the issues (overheating, squeeling, not starting) and they've informed me (if i can remember correctly) that they think the ecu has gone bad and might have to replace the pcm?

the ecu would cost 250 to replace but the pcm is going to cost me 2100?!!! im wondering what exactly a pcm is, what it does, and if there's anywhere i can get one for cheaper than that. possibly used?

any help would be appreciated.

thanks.

-Riebs

 

This sounds kinda fishy. A ECU would not normally affect overheating or cure a "squealing" noise. It COULD affect starting, but only to the point where if it was fried the vehicle would not start. Rough running once started-- can by a indicator of a damaged ECU. Give us more detailed info regarding each of these problem areas. As far as the "PCM" for $2100? No bells going off over that term. There is a "TCM" (transmission control module).

regards,

Geoman
www.eurotekapg.com

 

the vehicle began to squeel whenever i accelerated in gear. about two weeks later, it overheated and broke the reservoir. after replacing the reservoir and tightening the belts, it still overheated. i tried a few other things, and while i was test driving it a little while after i came to a stop and the car just died. i replaced the battery and it started up. it ran just fine. the next day i drove it to school and it overheated and died again at a stop light. i had it towed to the dealership where they just informed me that i need my PCM (powertrain control module) replaced. they say it's the main computer for the car and the part alone costs $2100. they say my wiring is fine and that the PCM is receiving power, but it's just not functioning.

-RIebs

 

Okay-- I've got some info for you. They are referring to a "ECM" (engine control module) with a factory part number of ERR 6759. According to ALLDATA, a professional repair and diagnostcs software that Pro shops use, the part lists for $2118.40, and the labor is .9 hour to replace it. This unit controls all of the engine management systems such as the ignition and fuel injection.

I'm gonna go out on a limb here and ask you a couple of questions. Did you, by any chance, powerwash the engine bay before these problems surfaced? and did the cooling system expansion tank (reservoir) drench the engine bay on that side of the vehicle when it blew at the seam? Reason I ask is that the ECM is on that side of the vehicle behind the main fuse box. It is possible to get moisture inside the ECM connector, and you can sometimes save them by drying out the unit after removing the power buss connector.

The thing I fear for you is that the overheating has done extensive damage. For a expansion tank to blow means there was high pressure in the system. The squealing noise may have been due to the fact that the water pump bearing was failing and starting to seize. They can go so bad as to allow the impeller to grind right through the timing case casting. Then the seal in the water pump fails very soon after, and the engine loses its coolant. When you say it overheated, did it peg the temp gage?

Back to the ECM---- you could try to find a used one from a dismantler, but I seem to remember they still want $400-500 for one. And it must be out of your same model year to avoid having to burn another program into the EPROM--something only a shop with a Autologic or Rovacomm unit can do.

Hope this info helps.

Regards,

Geoman
www.eurotekapg.com

 

ya, that sounds like we're talking about the same thing. and i assume the ecu and the ecm are totally different things? i think they already replaced the ecu, but i cant rememeber off the top of my head right now. im heading over to the dealership tomorrow morning and going to get the number off that part so i can try and replace it myself. if the ecm really is the problem, where does the pcm come into play? as for the overheating, it never got out of the red. i never let it get that hot. i'd heard about letting it get too hot and causing serious damage. the hottest i ever let it get was at the top of the red; so roughly 75% of the way to the peg. i have a new water pump and thermostat that im going to put in as soon i get the rover back.

 

Can't find any reference to a PCM on a Land Rover (even though the term is used on other Makes--and does stand for Powertrain control module). There is a BCM (body control module) for lighting and electrical distribution. A ECM is the same thing as a ECU. I do have a used ECM out of a Discovery we dismantled, but it is out of a early 1996. I'd sell it for $400, but we would have to match up part numbers before I would feel comfortable in recommending and selling it.

Geoman

 

so i went to the dealership this morning and finally figured out what they meant. i told the woman that i've been asking around and no one can find a reference to a PCM on a rover and i asked her if a PCM and an ECM are the same thing and she says, "oh yeah. ECM and PCM mean the same thing." 400 for a used ECM and 2100 for a new PCM is a big difference. sounds like a dealership con to me.

i got the part number off the ECM. the ECM that's fried's number is: AMR3242. The guy at the parts desk told me that there is a new ECM they put in there and it's part number is: ERR6802. If either of those numbers match up with the ECM you have then we're in buisness. if not i guess i'll have to look elsewhere.

thanks for all the help geoman. and thank god landroverforums was here to save me over a thousand dollars.

-riebs

 

I doing some more checking for you. The one I have has a part number of ERR 6355. However-- the ECM's out of the 1996-1999 GEMS vehicles are basically the same, with the difference being in the EPROM's inside. I'm thinking the only difference between what I have and yours may concern the advanced EVAP system your '97 has--but I'm trying to confirm this. Anyway-- I found the below information, and what is interesting is the part about your year vehicle having a intermittent "no-start" problem associated with the EPROM program. Sometimes it will crank but not start, and then other times it will not even crank over. There is a update program, but the shop has to have TestBook or Autologic unit to reprogram it.

Regards,
Geoman


GEMS No Start Security Update TSB.

--------------------------------------------------------------------------------

Intermittent Failure of Engine to Start
AFFECTED VEHICLE RANGE:
DISCOVERY (LJ) All GEMS Equipped
SITUATION:
ENGINE CRANKS BUT WILL NOT START OR INTERMITTENTLY WILL NOT CRANK
Intermittently the vehicle may not crank or crank and not start. Some or all of the following symptoms may be present:
^ The "Check Engine" light does not illuminate when the key is turned to position II (run).
^ A delay of 3 to 5 seconds between turning the key to position III (crank) and engine cranking.
^ After turning the key off (position I) then on again, the vehicle starts normally.
RESOLUTION:
* MODIFICATION OF THE IMMOBILIZATION STRATEGY *
The symptoms outlined indicate that the engine is temporarily immobilized due to a miscommunication between the security (10AS) ECU and GEMS ECM.
The technician must inspect and verify that two circuits and six electrical terminals are in good condition and working correctly as outlined in the repair instructions. When it is determined by the above electrical inspection that the fault is in the ECU, a security strategy modification can be performed to install the most current security ECU configuration. Use TestBook and the "Discovery Security Configuration" compact disk.
NOTE: The repairs outlined in this TIB are to be performed to resolve customer complaint of the symptoms described.


1. Remove the terminals from the connector housings to inspect the pin and socket terminals and the quality of the wiring crimps for each listed in the illustration.
2. Cautiously deform each pin and socket to improve connection.
3. Assemble connectors.
4. Use an ohmmeter to verify the continuity between the following:
^ C225 position 11 to C1032 position 22.
^ C225 position 15 to C1017 position 26.

5. Verify that neither circuit is short-circuited to vehicle ground.
6. If the tests verify the circuits and connectors are functioning correctly, perform selection of current immobilization strategy using TestBook.

* SELECTION OF CURRENT IMMOBILIZATION STRATEGY *
CAUTION: Any repair procedure that replaces the 10AS ECU will cause the GEMS ECM to relearn the security code. Depending on the configuration of the 10AS ECU installed, the GEMS ECM may re-enable the early immobilization strategy.
NOTE: The "Discovery Security Configuration," CD can be used to install the most current 1998 level of vehicle security. The new level of security will eliminate the intermittent failure-to-start symptom experienced on some 1996 and 1997 vehicles. The 1998 level of security continues to activate the horn and the lights and continues to inhibit engine cranking.