Think this might help others that are troubleshooting as myself, but still haven't found what the ECM/PCM controls. The thing that confuses me is that it appears neither the BCM nor the FCM would cause a no fire condition--so my next stop is ECM?
I cannot say that the following is specific to the Chrysler T&C, but is all I could find: The Front Control Module (FCM) is a micro controller based module located in the right front corner of the engine compartment. The front control module mates to the power distribution center to form the Integrated Power Module (IPM). The IPM connects directly to the battery and provides the primary means of circuit protection and power distribution for all vehicle electrical systems. The FCM controls power to some of these vehicle systems electrical and electromechanical loads based on inputs received from hard wired switch inputs and data received on the CAN bus circuit. OPERATION As messages are sent over the CAN bus circuit, the Front Control Module (FCM) reads these messages and controls power to some of the vehicles electrical systems by completing the circuit to ground (low side driver) or completing the circuit to 12 volt power (high side driver). The following functions are controlled by the FCM:
|
From what I can gather, the Engine Control Module provides the following features and is likely the source of my major problem of why it won't start? Thing is that it appears that may not end there. Please chime in for suggestions/recommendations:
electronic control module/unit ECM/ECU/PCM Controls ignition system's spark and timing, fuel system's fuel delivery and emission controls. Continuously receives signals from sensors and input devices on or near the engine; sends control signals to valves, controllers and other output devices. Stores "trouble codes" and warns driver when service is needed via check engine light or malfunction indicator light (MIL). PCM (Power Train Control Module) The powertrain or engine control module is a powerful computer that manages the engine’s ignition, fuel injection, and emission systems. In some vehicles, it may also control the operation of the automatic transmission and the anti-lock brake system. Symptoms of Wear or Failure · Check Engine Light illuminates with codes that cannot be repaired · Several unrelated trouble codes are set simultaneously · Vehicle may not start or run · Poor engine performance · Engine stalls while driving Related Repair Advice · Many vehicles have upgradeable software in their PCMs, so be sure to check for any Technical Service Bulletins (TSBs) that pertain to possible problems · When replacement is required, use a new factory PCM and install the latest software · A PCM can be mistakenly replaced when there was actually a defective engine sensor that was overlooked in the initial diagnosis · The terms PCM and ECM/U (engine control module/unit) are commonly used interchangeably. Technically, the ECM controls only engine-related functions, while the PCM controls engine and transmission operation. |
No spark. Check for B+ power at the coil connector or any of the coil driver outputs pulses from the PCM at the same connector. If power is missing you may have a bad PCM or the crank or cam sensor is toast. Lose either of those sensor inputs and the engine has no engine timing data to go by so it won't start and run. The van will crank all day, just won't start. No sensor code? They regularly fail without throwing a code.
|
OK. What is B+ power and how do I check that? I will have the mechanics at the hobby shop help me. BTW I did find a Chrysler dealer, but naturally they have to order any of these computer parts too! Of course they wouldn't offer me any suggestions having it towed to them for diagnostic. Since it is at a "repair shop" I'm having a hard time doing that. Also they don't work weekends and close before i get off work during weekdays. Talked to autocomputerexchange. They are helpful.
|
Been working late so haven't been able to work on it for past few days. Today had the mechanic run a full diagnostic. He could not get communication with the BCM. Both the crank and cam sensors tested good.
|
Well I got it fixed. It was the Body Control Module (BCM). There was only one available anywhere that I could find with the right model number, but found it on ebay. Now my van says that it has over 30,000 miles more than it actually has (the odometer reading is built into the BCM), but everything works. The dealer can flash the part to put the correct mileage but not sure it matters or worth the money to bring a 2001 back to 140K vs 172K.
Strange that the BCM affected things that are not mentioned as affecting such as spark or fuel systems or the instrument panel. I was told that if I put the BCM from another car without "flashing" it that it would cause the system to shut down. I figured that it couldn't hurt since the system was shut down anyhow. Well the truth is that you can replace the BCM and it will work with another vehicle. The unfortunate side affect is that you have to take whatever mileage the BCM shows (in my case +32K) or have the dealer flash your actual. Thanks for all your help. |
Hey Brownmal well i think that B+ became the brand for the high voltage in devices. It
became so conventional, that the phrase stayed when currents got a lot with solid-state devices.Thanks!! |
Hello Brownmal...seems like I have the same issue you had:
https://www.chryslerforum.com/forum/...tarting-20485/ Can you take a look and see if that's what you think it sounds the same. Also, was there a test you did of some kind to let you know it was def the BCM? Unfortunately, I only have 200 in savings, so really need to make sure am checking things to ensure it is the right part to replace before attempting. Any help would be appreciated, thanks! |
Wahoo! Got it stared and all the electronics working.
Looking at some suggestions online, I did the following, so not sure which one corrected the issue: disconnected the negative from the battery for about 2 hours pulled out and pushed back in each fuse and relay disconnected the positive and touched the positive and negative together for over a minute reconnected the positive and negative opened car door and instruments were on car started no codes being thrown.....yet |
Glad it worked out for you. Yes the BCM was the problem. I opened it and noticed the circuit board fried. Unfortunately there were only a few with my specific part number avail on the web...and all had significantly more miles than my actual. I didn't want to pay to get the mileage reset, so tried a few other BCMs on the web that were cheaper (3 others in fact!). The folks (even mechanics at the Chrysler dealerships I called) that said that doing so would blow the whole computer system--lie. Generally they worked--got the car running, but since mine was a Limited Edition, not all the electrical stuff worked. Such as power door locks or doors. Eventually I bought the bullet and paid for the expensive part. My van shows an additional 50K miles on the odometer, but everything works perfect.
|
All times are GMT -5. The time now is 07:35 AM. |
© 2024 MH Sub I, LLC dba Internet Brands