Codes U0100 and P3000

"I have a copy of Techstream and I'm not afraid to use it."
That's good. Have you used it to retrieve DTC from the traction battery ECU?

DTC P3000 is logged by the hybrid vehicle ECU and indicates the traction battery or the traction battery ECU has a problem.

DTC U0100, also logged by the HV ECU, indicates a communication error with the engine ECU.

 

I suggest you use the software to link to the traction battery ECU and review the parameters that can be displayed, especially module pair voltages and internal resistances. Look for any module readings that substantially differ from the other modules.

 

Hi Patrick, hoping you could help.

2004 525k miles, engine&trans form 44k donar 2 years ago so about 150k on ICE.

I get the triangle and ICE shuts down within a minute of a power cycle, flashing full tank on dash (actual level 2 bars)


Hybrid Control
P3000 CUR
U0100 CUR & PEND

HV Battery
U0100 PEND

ABS/VSC/TRAC
C1259 CUR
C1310 CUR

AC
B1412

I'm assuming these other repeater codes are caused by the sudden loss if communication.

Wife's 2006 provides parts to swap and so far I've pulled and inspected ALL fuses, the relays above valve cover have been swapped, the Integration Relay (both the one w/out fuses and the one with 4), replaced the combo meter (it was stuck on 299999 for the last 6 years), all wiring harness plugs re-seated after visual, zero corrosion found, checked all connections in HV block, and finally the battery ECM.

All parts turned out good and working in wifes car.

Am I correct in assuming since the codes are readable my OBD port and main ECU are good, and perhaps the ICE ECM located next to it is culpable? Any ideas greatly appreciated.

The SOC display showed battery operating nicely, plenty of power, no high revving associated with weak modules, just cruising 70 then on battery alone. Had to be towed home.

I have Techstream and mini VCI. Hoping to cap off this thread with a resolution.

Thank You!

 

I think your assumptions are valid. I'm amazed that this Prius is still on the road given the odometer reading.

I suggest you use a multimeter to see if you have 12VDC on pin 4 (on connector E7) of the engine ECU, when the Prius is IG-ON. The repair manual also shows several pins to verify that you have body ground at those pins. If you have correct voltage and ground at the appropriate pins, the troubleshooting tree suggests replacing the ECU.

Since it is relatively easy for you to swap and test parts with your other 2006 Prius, you may decide just to swap the ECUs and see what happens. (Athough you have to take apart most of the instrument panel to get to the ECU.)

If you find the 2004 engine ECU works OK on the 2006 Prius, then you may have a fault with the 2004 wiring harness.

 

Dash is apart on '04... was going to hold off on ECU swap only because it won't start without programming to VIN (need wife's car to remain in service).

Taking voltometer to pin 4 next. Hoping to solve this weekend so you're awesome in replying so soon!

 

Kept main and ICE together, pulled from '04 and plugged into '06 I cannot start it of course due to VIN programming not performed.

NO triangle. The test passed, because even if you only press Power button twice in '04 it throws codes.

Gas gauge showing correctly and NOT blinking with my '04 ECM/ECU in '06.

Too difficult to rip apart '06 to reverse the test.

Stand by, putting it back into '04 and testing for 12v next. What's likely if no power to that pin?

 

I do not believe that the engine ECU needs to be programmed. It is true that the hybrid vehicle ECU and the immobilizer ECU need to be programmed to the vehicle they are installed in.

 

Unfortunately it passed the test, 11.83v in ready. Remains powered after resetting codes and Triangle.

The wiring and harness and connectors all look amazing for such an old car. Grounds are good. No areas getting scuffed or rubbed upon complete visual inspection.

Any ideas to try greatly welcomed.

 

Did you try moving the 2004 engine ECU by itself, to the 2006 Prius? See if the 2006 will start without posting DTC.

 

When you click on the snowflake icons in Techstream, what additional information is displayed?

 

Yes just drove the '06 with my '04 ICE ECM in her. Zero issues.

 

I get additional info. Please see attached photos. Thank you.

 

Seems like a wiring harness problem which will not be easy to find. Basically you would have to download the electrical wiring diagram and check the wires associated with the vehicle communication network.

 

Hybrid 911 Mechanic making a house call tomorrow morning. They repaired battery years ago so that's how I found them.

They did the motor swap a couple years ago as well. We will have this solved tomorrow and I promise to share results.

Labor should be minimal beyond troubleshooting time as I've got her as pulled apart as can be.

Thank you again!

 

From the snowflake screen shots, you now have the INF codes displayed as well as representative values to help determine the cause.

This helps narrow down the next steps .

If you want to minimize the troubleshooting time tomorrow, research the troubleshooting procedures prior to the mobile mechanic arriving.

Good luck tomorrow and keep us posted.

 

The great thing about these forums is somebody may not have to shell out $525 to have mechanic troubleshoot if a reader is experiencing this same issue - easy test..

Simply unplug the following $77 part:
Genuine Toyota 16670-21010 Water Valve Assembly Valve With Bracket

So its almost 3 here, running to Toyota for a replacement. I've been given no assurance that will solve it. But you can drive it around 20 minutes no problem if unplugged. Comms restored until plugged back in.

Harness was given clean bill of health.

 

There's the culprit. 100% back to perfection. About 45 minute job.

I do sincerely wish the machine was smart enough to have a DTC code thrown when water valve goes bad.

Would have saved me hundreds, and many hours, knowing what I know now (disconnect it and drive vs. $310 tow... 3 hours and a trip fee for mechanic to pinpoint for me $525... $103 for new valve and a gal of coolant.)

$928 total for a part online as low as $67 bucks.

Still could not be happier. What do you expect once you've commuted to the half-million mile club, right?

Side note: noticed my rad was weeping, so tossed a new one in tonight as well. Included a pic. It had far more dirt trapped in the fins than I could have ever imagined.
$77 bucks well spent.

 

Very interesting - apparently that engine coolant valve's failure introduced sufficient electrical noise into the engine ECU to take that ECU offline from the vehicle communications network. Thanks for providing new knowledge for the Prius "hive".