03 still won't start. Only DTC 1259

DTC C1259 is produced by the brake ECU.

A simple item to check: do you have the orange interlock plug properly installed? You need to insert the plug, pivot the handle 90 degrees, then slide the handle to lock.

 

The '03 doesn't have the funny pivot-handle. But the service
plug is one thing to check. If one wire was cut between the
ECU and inverter, all the harnesses are worth a close look. How
did the one get cut? Another thing to look at is bring up all
the battery-block voltages in AE and make sure they're all
about the same, and see what they do when you try to go to READY
[if you even can at all]. What version of AE do you have? It
took until 5.1 or thereabouts before they really had it right
for Priuses in general, I think.
.
_H*

 

From the manual, pp DI-443:

Malfunction in HV ECU

DTC Detecting Conditions:

The conditions 1 to 3 continue for 0.02 sec.
1. Voltage of the terminal IG2 in brake ECU is 10.5 V or more and continues for 1.5 sec.
2. Regenerative malfunction occurs on HV ECU side
3. Received data is accepted as valid

Trouble Area

HV control system
HV ECU

INSPECTION PROCEDURE

1. Check DTC for the HV control system
1. Repair HV control system according to the code
2. Check that HV ECU is connected to indicator light
​

* * *
No P codes?

Bob Wilson

 

C1259 is not preventing the engine from starting.

If you are getting a READY signal, then you have no service plug issue.

As noted in the previous thread, you need a battery pack.

 

The CRUISE light should come on once the car is READY and you turn the CC switch on. The car doesn't have to be moving.

 

Change the 'subsystem,' (I'm not in front of my AE but it is how you select which ECU you're monitoring) to the HV ECU. Then go to the "Live Data" and select the accelerator inputs. See if pressing the accelerator shows a change in value. This verifies that the HV ECU is reading at least those inputs.

If this passes, I would enable all inputs and one-by-one check to see that the HV ECU is reporting them to AE.

Tedious, but sometimes you have to 'work for an answer.' Also, keep a weather eye on the Aux battery voltage. Be careful and try to avoid having too many things plugged into the car from separate AC power sources ... no need for a ground loop at this late date.

Bob Wilson

 

Actually, AE ver 8.2 is the first version to work with the 03 prius. They also have ver 8.2.1 now, but the only improvement there is for the 06. So keep 8.2 and look at the "HV Battery" interface - all block voltages, and see what happens when it tries to spin the ICE for start up. You may want to save this data as a .csv file to review later. If any block voltage falls below about 6.5V during startup, it will never try again. Oh and remove the 12V battery neg for ten minutes b4 trying this to clear codes. If real it will come back immediately. Good luck

 

Almost forgot here is a shot of the systems covered by AE in the 03.
"no response from CCS module" with version 8.2 on the 00-03 is correct.

 

There is.

Not necessarily.

Was that before or after you started this thread?

You won't see that until you get the vehicle to go READY and stay there. But I wouldn't be looking at cruise control issues to diagnose a no-start.

 

Did the vehicle exhibit the same behavior prior to HV ECU replacement; i.e. READY for a few seconds before shutting down?

 

was this vehicle crashed? it sounds like there is a communication problem with one or more of the ECUs, im basing this on the assumption that there are no codes with prefix of P

im making a big hunch here, i think theres a problem the HV ECU connections.

 

Then last month's diagnosis still stands. However, the vehicle will refuse to start even after the root cause is corrected, unless the original HV ECU is reinstalled or the replacement HV ECU is reprogrammed.