TSB: Code P0125

Just for general knowledge:
The Technical Service Bulletin [TSB] T-SB-0088-08 applies to 2004 through 2007 models.

ZC1

 

What is an "M.I.L."?

 

Malfunction Indicator Light

 

aka the amber warning light that looks like a little engine.

 

Note that subject TSB T-SB-0088-08 requires ECM calibration ID 34705400 to be uploaded to the ECM for 2004-2005 models. Prior to this TSB being released, I had seen TSB EG047-04 which related to an engine no-start or low power situation (file attached below.) That TSB required ECM calibration ID 34705100 to be uploaded to the ECM.

My question relates to ECM calibration IDs 34705200 and 34705300. Has anyone seen a TSB or other technical documentation that describes what those firmware changes were intended to correct?

The reason that I've been looking at powertrain-related TSBs is because I noticed some power surging when driving my 2004 (64K miles) on a trip to Palm Springs earlier this week. No warning lights.

Ambient temps were moderate in the early evening, I had the air conditioning off. The surging got to the point where I was thinking about where I could safely pull over on I-10 in case the car stalled. However, the drivetrain then resumed normal behavior and I continued my trip without further incident.

 

Pray excuse me for reviving so old a thread. Is this still, perhaps, a relevant issue?

I ask because I continue to get an MIL/CEL for P0125 despite having replaced the thermostat just 3 weeks ago. Perhaps the sensor is bad, but wouldn't it have come back sooner, if that was the case? Furthermore, I typically notice the MIL return in the morning after the car has been in READY- Park for 8+ hours (it's my motorhome).

Replacing the sensor shouldn't be too much of a hassle, but Autozone wanted $70. I haven't checked prices online yet

 

i would start a new thread

 

if anyone needs the update cuw attached.

having an issue connecting the ECM update wizard from techstream 16.10.016 using the cables... any idea if I need a newer version cable or older techstream version?

 

Not all Techstream installations are capable of updating ECU, and personally, I would not try and do this myself. Rather I'd take it to Toyota, especially if there was still an active TSB out for the issue you're having. That way, if the car gets bricked it is Toyota's problem to fix rather than yours. The other thing to consider, it is very unlikely Toyota would have issues updating the ECU. On the other hand, chances are higher that you might brick the ECU given you will be using an uncertified cable and software.

I guess the other option is to secure another ECU with the required level of calibration ID and install that.