Random Computer / CANBUS problem?

[delf]

2011 RAM 1500, 5.7L, 110K miles.

Just began having a problem with no crank/no start this week. Checked OBDII with BlueDriver and got these codes:

U1197 Security Seed Response Not Received from ECM/PCM
U0121 Lost Comms with anti-lock brake system (ABS) control Module "A"
B1630 Right low beam control circuit high
B162C Left low beam control circuit high
B1638 Right Hi beam control circuit high
B1634 Left hi beam control circuit high
U0212 Lost comms with anti-lock brake system (ABS) control module "A"
B1D36 Pax mirror heater control circuit/performance : circuit short to battery or open
B105D Recirculation door travel range too large
B1058 Recirculation door control circuit/performance " performance or incorrect operation
B1629 Cargo lamp control circuit open
B212C Ignition Run/Start Input circuit open ; circuit open
U0121 Lost coms with anti-lock brake system (ABS) control module "A"
P0513 Invalid SKIM Key
P1521 Incorrect Oil type

The day this began was in the morning, in my drive fortunately, and the engine started normally and died after about 2 ~ 3 seconds. It had never done that before. Trying to restart failed, no clicking, no indication that it was trying to crank. All other functions appeared to operate normally (lights, door locks, fan blower, turn signals, etc.) The security light was blinking which was new. I used the OBDII reader and got the list shown above. Initially I thought the 4-year-old battery might be the culprit even through a tester indicated its capacity was around 75%. I replaced it and after a couple of tries it started and ran normally for a couple of days. I figured the battery was the issue after all.

Two days later the same thing occurred though this time it didn't even crank. All the same symptoms. Battery checked out with 100% capacity and nominal voltage. OBDII check list looked pretty much the same as before (shown above).

The only thing that has changed on this truck was that I replaced all headlight bulbs and the cargo lamp bulbs a week prior with LEDs. All appeared to work normally the one time I drove after dark. I know there are cases where LED lights do not function properly due to compatibility issues that show up as CANBUS problems.

Does it seem feasible that the LEDs are causing this problem? Clearly there's an issue that is causing the computer(s) to report a rash of problems. I can clear all the codes and it remains clear of codes until the next time when the whole list is presented at the same time. I'm thinking of reverting to regular halogen bulbs for the headlights and cargo bay lights in the interim. At least if the problem persists I'll know they were not the cause.

Any other ideas, suggestions?

 

[Harley Harrold]

 

[Dredger]

That's quite an assortment of unrelated codes. It really sounds like your battery, again. What's "nominal" voltage - do you have a number? Will it start if you charge the battery? Have you had your alternator checked? Did you end up reverting back to the original bulbs?

 

[RamDiver]

Load test the battery with a toaster-style battery load tester not a digital tester.

It sounds like you may have something drawing current and killing your batteries.

You might add a battery tender as a temporary band-aid and see if that clears out all those DTCs.


And, to Ram Forum.

.

 

[Papa Red]

Welcome to the forum.

Red

 

[delf]

Not the battery. Installed a new one and same issue. I have not reverted back to orignal bulbs yet, am awaiting resistor harnesses for the LED lamps and will see if the codes for the headlights go away.

The failure to crank has happened three times now and the same codes show up. I'm of the opinion now that it's a CAN BUS issue, either an internittent open or short, or a module on the BUS acting up. What makes this painful is that I do not get a hard failure at convenient times so I can't troubleshoot it until it happens again and I have the right instuments and electrical diagrams with me. I now have the AllData wiring diagrams, specifically the CAN BUS diagrams with connector locations.

Of course when the thing is running the voltage at the DLC is correct for C+ and C-, and looks fine on the scope. I will be looking at the list of codes and determine if they're all on the same BUS and narrow the search field down.

I recalled after my first posting that I had seen most of these same codes when I ran a system scan after buying the truck from my brother and getting back home in another state, just to see if there were any issues that might need attention. Most of the codes listed above showed up then (but I don't recall the lights being in the list then). I assumed they were just old. That was 4 months ago. This makes me think that the light codes are legit but have no bearing on the rest of the list. The fact that all of the other seemingly unrelated codes were there before all of this started seems to point to a CAN BUS issue that is progressively worsening. Those "lost communications" codes sort of point in that direction.

 

[Daw14]

Lots of large wiring harness connections under hood seem to get corrosion issues after so many years, maybe you will have some luck pulling them apart and cleaning then resetting them.

 

[delf]

Agreed - that's what I expect it to come down to. I'm still sorting through the can bus diagrams and wiring diagrams to get an overview of what I'm in for.

Yesterday I adedd the resistor harnesses to the hi and low beam headlights. I no longer get the codes complaining about the lights. Now waiting for the next no-crank symptom to go onto the bus wiring with a scope and diagnostic tablet and hope to isolate the area causing this issue.

 

[delf]

It's been a month since last posting here. A couple of weeks ago the truck died while in traffic on the interstate. I had enough momentum to get the truck off on the shoulder. It quit just as if I had turned off the ignition, though all other functions continues. It would not crank. I put the scanner on it and found no codes. AAA picked it up after a three hour wait. When it was delivered home, it would crank and run. This has happened a couple more times since, the last time just a couple of days ago, in the driveway. No crank though everything else functioned. I checked the output of the WIN (ignition) and it showed that Ignition/Run/Start line go high but nothing happened. I cannot determine from the AllData schematics just how the actual crank signal is generated. The scanner shows the ignition switch functioning as it should. Also, I tried the remote start and it did honk twice, but no crank. This is the same behavior I saw weeks earlier - two honks, no crank. When it did run I wiggled/pulled on all relevant connectors and wires to try to get the engine to die, but no joy there. I swapped the K4 relay (run relay) with no change in behavior. It does not appear to be a loose/intermittent connection or marginal relay so far. I'm beginning to suspect the TIPM. I did pull the TIPM and clean all connectors, used contact cleaner - it all looked pristine, no corrosion anywhere. What makes this so difficult to diagnose is that it will not remain in a no-crank state long enough to trace out the circuits from the WIN to the TIPM. It just starts working before I can get very far down that path. Just to reiterate, I'm getting no codes for this.

Anyone know just how the actual crank signal is generated from the WIN module? There's no theory of operation description for this in AllData.

Just to clarify my thinking - I don't believe this is a starter issue as a starter would have no bearing on a running engine just shutting off unexpectedly. What makes this such a headache to diagnose it that when it fails, it will not remain in a failed state long enough to crawl through the circuits to see where signals are missing.

 

[dchapma1957]

It's been a month since last posting here. A couple of weeks ago the truck died while in traffic on the interstate. I had enough momentum to get the truck off on the shoulder. It quit just as if I had turned off the ignition, though all other functions continues. It would not crank. I put the scanner on it and found no codes. AAA picked it up after a three hour wait. When it was delivered home, it would crank and run. This has happened a couple more times since, the last time just a couple of days ago, in the driveway. No crank though everything else functioned. I checked the output of the WIN (ignition) and it showed that Ignition/Run/Start line go high but nothing happened. I cannot determine from the AllData schematics just how the actual crank signal is generated. The scanner shows the ignition switch functioning as it should. Also, I tried the remote start and it did honk twice, but no crank. This is the same behavior I saw weeks earlier - two honks, no crank. When it did run I wiggled/pulled on all relevant connectors and wires to try to get the engine to die, but no joy there. I swapped the K4 relay (run relay) with no change in behavior. It does not appear to be a loose/intermittent connection or marginal relay so far. I'm beginning to suspect the TIPM. I did pull the TIPM and clean all connectors, used contact cleaner - it all looked pristine, no corrosion anywhere. What makes this so difficult to diagnose is that it will not remain in a no-crank state long enough to trace out the circuits from the WIN to the TIPM. It just starts working before I can get very far down that path. Just to reiterate, I'm getting no codes for this.

Anyone know just how the actual crank signal is generated from the WIN module? There's no theory of operation description for this in AllData.

Just to clarify my thinking - I don't believe this is a starter issue as a starter would have no bearing on a running engine just shutting off unexpectedly. What makes this such a headache to diagnose it that when it fails, it will not remain in a failed state long enough to crawl through the circuits to see where signals are missing.

I just went through something very similar, no crack, no start and flashing red security light on the dash - the result of the U1197 Security Seed Response Not Received from ECM/PCM. Mine turned out to be a faulty R4 Run/Stop relay but I see you have already swapped yours out.

I do believe your issue is in the TIPM, or connections on it.

Theory:
When you first turn the key to to Run the WIN modules reads the code from the key via RFID.
The Win send the Key values to the PCM and waits for a reply that the Key is for the vehicle. If no PCM response is received the U1197 is posted and you get the flashing red security light on the dash.

R4 Run Stop is energized as soon as the key is moved to the run position. It in turn powers a bunch of stuff including sending +12V to the PCM on connector C1 - Pin 12 I believe. If this 12V is missing the PCM is not powered up enough to reply to the WIN handshake.

If the WIN DOES receive the proper handshake reply from the PCM I believe it send a message over the CAN Bus to the TIPM to actuate the starter relay. (This is my opinion - I too have not found any definitive theory of operation).

I also believe if the Relay R4 drops out for some reason while driving it will shut you down. (This happened to me - just died on me).

I have since replaced R4 with a new relay, (actually I replaced a bunch of them for kicks) and I have not had any issues since. This drove me crazy for two weeks - I even had it towed to a garage and they gave up on fixing it so I had it towed home. I spent a lot of hours verifying voltages, CAN Bus continuity, etc. I even ordered up a rebuilt TIPM but ended up not using it. The place I used allows a "rental" for the first 30 days for a restocking fee of $120.

 

[Slinge]

I just went through something very similar, no crack, no start and flashing red security light on the dash - the result of the U1197 Security Seed Response Not Received from ECM/PCM. Mine turned out to be a faulty R4 Run/Stop relay but I see you have already swapped yours out.

I do believe your issue is in the TIPM, or connections on it.

Theory:
When you first turn the key to to Run the WIN modules reads the code from the key via RFID.
The Win send the Key values to the PCM and waits for a reply that the Key is for the vehicle. If no PCM response is received the U1197 is posted and you get the flashing red security light on the dash.

R4 Run Stop is energized as soon as the key is moved to the run position. It in turn powers a bunch of stuff including sending +12V to the PCM on connector C1 - Pin 12 I believe. If this 12V is missing the PCM is not powered up enough to reply to the WIN handshake.

If the WIN DOES receive the proper handshake reply from the PCM I believe it send a message over the CAN Bus to the TIPM to actuate the starter relay. (This is my opinion - I too have not found any definitive theory of operation).

I also believe if the Relay R4 drops out for some reason while driving it will shut you down. (This happened to me - just died on me).

I have since replaced R4 with a new relay, (actually I replaced a bunch of them for kicks) and I have not had any issues since. This drove me crazy for two weeks - I even had it towed to a garage and they gave up on fixing it so I had it towed home. I spent a lot of hours verifying voltages, CAN Bus continuity, etc. I even ordered up a rebuilt TIPM but ended up not using it. The place I used allows a "rental" for the first 30 days for a restocking fee of $120.

Did you take the relay apart ?

 

[dchapma1957]

Did you take the relay apart ?

Yes, I did. The contacts were OK, but the coil measured ~750 Ohms and a good relay measured around ~90 Ohms. So the coil portion was shot.

 

[delf]

Since my last post I had replaced the WIN module and the problem seemed to be resolved. For about a week. Then the 'No Crank' issue popped up again. At this point the only thing left that made any sense was the TIPM. Picked up a refurbed unit and installed with no issues. That was two months ago. Since then I've had NO issues with cranking or starting. Don't know what the issue was with the TIPM - would have been nice to know. (Yes, I had swapped the start/run relay with one like it which made no difference).

 

[Daw14]

Glad to hear you are up and running consistently again. Thanks for sharing this, hopefully others will benefit.