(P)ECM Code 606

[Silver Tex]

Eliminating the RV as an X factor...

Trust, but Verify, the 5th wheel when disconnected from truck is at 12v on an internal outlet.

Check the RV batteries for tight connections and cable condition, every inch. (Same for truck positive cables.) One battery positive cable short was causing all kinds of ECM nightmares on a rig, but, didn't burn it to the ground. We were down to inspecting every inch of wire at that point. Under load the engine leaned into the cable causing a short, would loose ign and power and unshort, then fire back up violently.

Probe the following two connections on the truck and 5th wheel:
+ Auxiliary: looking for battery voltage in reference to A ground.
Ground : test for voltage in reference to A Ground first and then resistance that should be "0".

"A Ground" is any ground on the 5er or truck under test.

Then measure battery voltage on each and write down.
Plug in the 5th wheel and remeasure and write down.

Start the truck and remeasure the battery voltage on the truck and 5er and write down.

Next with the truck running measure voltage between "A Ground" on the truck and "A Ground" on the 5th wheel. We are looking for a possible bad ground with this test.

Now do a wiggle test on the wire coming out of the trailer plug and at the 5th wheel. We are looking for loose wires, broken wires, or shorts in the plug or wire near it. Measure the ground voltage between them as above and the charging voltage at the RV while doing this test. I use an analog meter as digital won't show a problem aka a needle jumping during wiggle tests.

Verify all the lights work properly like turn signals etc on the 5th wheel. Looking for any wiring screw-ups.

Someone will have to chime in on specific Dodge setups: I am used to installing a 30A breaker under the hood for the Aux trailer battery charging. Sometimes it is off a larger fuse to the breaker.

View attachment 117676

OK! That is a very comprehensive test procedure. I’ll report back. It won’t be for awhile as it’s Christmas . Any further comment or thoughts on the ECM voltage (via Smarty Touch) running voltage at 14.7v or 14.8v? It seems about right to me and I tried to find the operational criteria through my Alldatadiy subscription, but have not found yet. Thanks All and again Merry Christmas!
Scott.

 

[AH64ID]

ECM voltage is fine.

You certainly need to see if you can duplicate it with the 5th wheel or if it was a coincidence.

 

[Silver Tex]

ECM voltage is fine.

You certainly need to see if you can duplicate it with the 5th wheel or if it was a coincidence.

Copy that and will do!
Thank you.
Scott.

 

[Tuesdak]

Further thoughts after you verify the RV is ok.

Take a hammer and administer a "Static Vibration Test" to the ECM while the engine is running. Not hard, just tap on it to see if anything is loose/cracked in it and will trip a code. I learned this "tap on things" from a GM dealer on a 1985 Olds 98. Car had stalled out on Soldier Summit in Utah in 1996. Had to tow it and then it starts and runs fine for a year afterwards. Then it starts randomly stalling out blowing black smoke and the primitive 1980's ECM is useless/clueless. Olds Dealer tapped on the MAF (Mass Airflow Sensor) and the engine would flood and stall out due to a bad connection in the MAF. Turns out GM had a bad run of those and most failed a decade earlier. (I hate FWD as it really kicks back the wheel when the engine goes Boat Anchor in a 90 degree turn before the auto trans lets go from driving a dead engine... then having to brute force crank the wheel further to finish the turn while wedged up against the door.) A recall (of course there wasn't one) of the defective MAF sensors could have prevented a accident had I not been strong enough to finish the turn.

Have your ECM rebuilt and here is why: No, not exchanged: Your ECM rebuilt.

You should get a report from the electronics repair shop as to what they found wrong with it. Bad memory, bad chip on board, bad cap... But the most common failure to ECM's and automotive electronics is bad connections. Specifically cracked solder joints. Some ECM's are known to crack joints on the vehicle plug (wire connectors) to the board. Corrosion in the ECM can also be a cause.

If the electronics shop can't find anything wrong with the ECM "Welcome to Ripley's Believe It or Not!" where fiction has to be plausible but the truth does not. Intermittent electronic problems are a real PIA to hunt down. After checking everything you can with a your test good ECM I would suggest you replace ECM with new as yours may have an intermittent problem that isn't worth the aggravation to put up with.

If you want to look at other things:
Check the battery charge wire off the alternator for being loose or corroded.
Test alternator for "noise" like bad diodes.
Remove and clean battery grounds on engine in case corrosion is hidden.
I am not sure if there is a ground strap from the engine to the frame or if it is just the 2 wires from the battery negatives to fenders - take apart and clean em.
Hunt down ECM ground and clean.

 

[Silver Tex]

Further thoughts after you verify the RV is ok.

Take a hammer and administer a "Static Vibration Test" to the ECM while the engine is running. Not hard, just tap on it to see if anything is loose/cracked in it and will trip a code. I learned this "tap on things" from a GM dealer on a 1985 Olds 98. Car had stalled out on Soldier Summit in Utah in 1996. Had to tow it and then it starts and runs fine for a year afterwards. Then it starts randomly stalling out blowing black smoke and the primitive 1980's ECM is useless/clueless. Olds Dealer tapped on the MAF (Mass Airflow Sensor) and the engine would flood and stall out due to a bad connection in the MAF. Turns out GM had a bad run of those and most failed a decade earlier. (I hate FWD as it really kicks back the wheel when the engine goes Boat Anchor in a 90 degree turn before the auto trans lets go from driving a dead engine... then having to brute force crank the wheel further to finish the turn while wedged up against the door.) A recall (of course there wasn't one) of the defective MAF sensors could have prevented a accident had I not been strong enough to finish the turn.

Have your ECM rebuilt and here is why: No, not exchanged: Your ECM rebuilt.

You should get a report from the electronics repair shop as to what they found wrong with it. Bad memory, bad chip on board, bad cap... But the most common failure to ECM's and automotive electronics is bad connections. Specifically cracked solder joints. Some ECM's are known to crack joints on the vehicle plug (wire connectors) to the board. Corrosion in the ECM can also be a cause.

If the electronics shop can't find anything wrong with the ECM "Welcome to Ripley's Believe It or Not!" where fiction has to be plausible but the truth does not. Intermittent electronic problems are a real PIA to hunt down. After checking everything you can with a your test good ECM I would suggest you replace ECM with new as yours may have an intermittent problem that isn't worth the aggravation to put up with.

If you want to look at other things:
Check the battery charge wire off the alternator for being loose or corroded.
Test alternator for "noise" like bad diodes.
Remove and clean battery grounds on engine in case corrosion is hidden.
I am not sure if there is a ground strap from the engine to the frame or if it is just the 2 wires from the battery negatives to fenders - take apart and clean em.
Hunt down ECM ground and clean.

Thanks Tuesdak for the comprehensive procedures.
Happy New Year!
Scott.

 

[Silver Tex]

Hello,
So I am back again with some added information and yet another question. I left the truck sit for the last month in the shop, went to start it yesterday and the batteries were dead, this after they tested good. It seems as though I have some sort of parasitic (sp?) drain. Would a bad ECM cause this type of a drain. The shop isn’t heated but it doesn’t get much below 35 degrees in there and the doors are rarely opened except on nice days.
I’ll move on to the RV issue once I figure out why the batteries go dead while sitting. Any thoughts will be appreciated. I’ll check all the cable connections.
Thanks all!
Scott.

Further thoughts after you verify the RV is ok.

Take a hammer and administer a "Static Vibration Test" to the ECM while the engine is running. Not hard, just tap on it to see if anything is loose/cracked in it and will trip a code. I learned this "tap on things" from a GM dealer on a 1985 Olds 98. Car had stalled out on Soldier Summit in Utah in 1996. Had to tow it and then it starts and runs fine for a year afterwards. Then it starts randomly stalling out blowing black smoke and the primitive 1980's ECM is useless/clueless. Olds Dealer tapped on the MAF (Mass Airflow Sensor) and the engine would flood and stall out due to a bad connection in the MAF. Turns out GM had a bad run of those and most failed a decade earlier. (I hate FWD as it really kicks back the wheel when the engine goes Boat Anchor in a 90 degree turn before the auto trans lets go from driving a dead engine... then having to brute force crank the wheel further to finish the turn while wedged up against the door.) A recall (of course there wasn't one) of the defective MAF sensors could have prevented a accident had I not been strong enough to finish the turn.

Have your ECM rebuilt and here is why: No, not exchanged: Your ECM rebuilt.

You should get a report from the electronics repair shop as to what they found wrong with it. Bad memory, bad chip on board, bad cap... But the most common failure to ECM's and automotive electronics is bad connections. Specifically cracked solder joints. Some ECM's are known to crack joints on the vehicle plug (wire connectors) to the board. Corrosion in the ECM can also be a cause.

If the electronics shop can't find anything wrong with the ECM "Welcome to Ripley's Believe It or Not!" where fiction has to be plausible but the truth does not. Intermittent electronic problems are a real PIA to hunt down. After checking everything you can with a your test good ECM I would suggest you replace ECM with new as yours may have an intermittent problem that isn't worth the aggravation to put up with.

If you want to look at other things:
Check the battery charge wire off the alternator for being loose or corroded.
Test alternator for "noise" like bad diodes.
Remove and clean battery grounds on engine in case corrosion is hidden.
I am not sure if there is a ground strap from the engine to the frame or if it is just the 2 wires from the battery negatives to fenders - take apart and clean em.
Hunt down ECM ground and clean.

 

[Prairie Dog]

Don't charge your 5er batteries off the truck. If your 5er batts. are low and truck batts. aren't you will cause overcharging.

I'm sorry but that's not how it works.
If the batteries in the trailer are at a higher charge than the truck batteries, they simply wont pull any more current from the trucks system and will slowly drop to the systems overall voltage level (equalize).
The oposite is true as well. If they are at a low state of charge, they will have a lower internal resisitance and they will again, pull or draw power from the system. The trucks batterys wont over charge because their internal resisitance is relatively high.
Basically, an alternator doesn't put out power so much as the things in the circuit take said power.

Best regards,
Scott

 

[Tuesdak]

Hello,
So I am back again with some added information and yet another question. I left the truck sit for the last month in the shop, went to start it yesterday and the batteries were dead, this after they tested good. It seems as though I have some sort of parasitic (sp?) drain. Would a bad ECM cause this type of a drain. The shop isn’t heated but it doesn’t get much below 35 degrees in there and the doors are rarely opened except on nice days.
I’ll move on to the RV issue once I figure out why the batteries go dead while sitting. Any thoughts will be appreciated. I’ll check all the cable connections.
Thanks all!
Scott.

Some Dodge trucks have a Ignition-Off Draw fuse you can pull for long term storage. It's best to have an automatic charger on things stored that long. You have a ECM memory and radio clock that draws some current with the key off. This fuse kills power to those.

Some vehicles eat batteries alive in storage because some drains are not noticed when run often. My favorite is the brake lights randomly staying on or a worn out horn switch blowing the horn in cold weather but stopping when it warms up. (The vehicle I dealt with this on actually blew the horn in the middle of the cold night... and eventually required replacement of the horn switch, fuse, horn relay, and burned out horn itself. Of course the switch was the last to get replaced as it was intermittent.)

Regardless you can do an amp draw test and see what the key off amp draw is. Example of how to do this below. Their solution is drastic because they couldn't find the exact 4 Amp draw - I would have just pulled the offending Ignition-Off Draw fuse they narrowed it down to. Just saying because you would pull that fuse for storage anyway. You can narrow down where the draw is. Do consider battery self discharge and problems in a/both battery as 30 days is a lot to ask of automotive batteries in storage with parasitic loads connected.

http://www.trucktrend.com/how-to/interior-electrical/1603-fixing-that-dead-battery-problem/

 

[Silver Tex]

Some Dodge trucks have a Ignition-Off Draw fuse you can pull for long term storage. It's best to have an automatic charger on things stored that long. You have a ECM memory and radio clock that draws some current with the key off. This fuse kills power to those.

Some vehicles eat batteries alive in storage because some drains are not noticed when run often. My favorite is the brake lights randomly staying on or a worn out horn switch blowing the horn in cold weather but stopping when it warms up. (The vehicle I dealt with this on actually blew the horn in the middle of the cold night... and eventually required replacement of the horn switch, fuse, horn relay, and burned out horn itself. Of course the switch was the last to get replaced as it was intermittent.)

Regardless you can do an amp draw test and see what the key off amp draw is. Example of how to do this below. Their solution is drastic because they couldn't find the exact 4 Amp draw - I would have just pulled the offending Ignition-Off Draw fuse they narrowed it down to. Just saying because you would pull that fuse for storage anyway. You can narrow down where the draw is. Do consider battery self discharge and problems in a/both battery as 30 days is a lot to ask of automotive batteries in storage with parasitic loads connected.

http://www.trucktrend.com/how-to/interior-electrical/1603-fixing-that-dead-battery-problem/

Thanks Tuesdak,
Great points! I did a some research on testing for a parasitic drain (draw) and found something similar to what you linked to. An interesting development. My low washer light comes on, even when full. I’ve read certain kinds of fluids can trick the sensors. I think I’ll perform the draw check to determine if I have a significant draw and will certainly pull the fuse you reference when I expect it to site for longer periods. Maybe I should drive it a little more often .
Scott.