AfterMarketNews Auto Care Pro AutoProJobs Auto-Video.com Brake&Frontend BodyShopBusiness Counterman EngineBuilder Fleet Equipment ImportCar Motorcycle & Powersports News Servicio Automotriz Shop Owner Tire Review Tech Shop Tomorrow's Tech Underhood Service

Second-rate parts mean second-rate results

When it comes to diagnosing a problem, one of the biggest mistakes is thinking that the problem is gone after you’ve installed a new part. I’ve had vehicles brought in countless times with the same old story attached to them. The customer will say:...

Read more...

GearWrench Launches Street Team, a New Mobile Driver Program

GearWrench, a premier hand tool brand from Apex Tool Group, has announced Street Team, a new program that gives independent mobile distributors the support of an established tool brand without the restrictions of a franchise. "Response to the program...

Read more...

AUTO 7 Named Approved Vendor For Automotive Parts Associates

Steven Kruss, president of Auto 7, which supplies Korean-made, OEM-quality automotive parts to distributors across North America, announced that Auto 7 has been named an approved vendor of Automotive Parts Associates (APA), one of the nation’s...

Read more...

Internal Engine Oil Consumption Diagnostics

Due to the variables in engine design and ­operating conditions, internal engine oil ­consumption complaints are often the most difficult to solve. In some cases, oil consumption might be more severe under low-speed operation, in other cases, high-speed...

Read more...

Hyundai Fuel System, Emissions Diagnostics

Hyundai has done a good job of improving its ­offerings over the years from both an aesthetic and mechanical viewpoint. Complemented by a strong warranty and good value, the carmaker has been able to increase its market share year over year. If you aren’t...

Read more...

Curing Volvo Manual Transmission Rattle

In an effort to increase fuel efficiency, today’s engines produce more torque so they can be ­driven at extremely low rpm. ­Reduced viscosity engine and gearbox oils, less vehicle weight and improved aerodynamics also contribute to better fuel economy....

Read more...

Talk To All Available Modules With Autel's MaxiDiag Elite MD802

Derived from Autel’s Professional Series tool, the MaxiDAS DS708, the MaxiDiag Elite MD802 enables the user to not only get into the OE enhanced OBD II system with mode 6 access and live data graphing, but it also allows a technician to scan the...

Read more...

Reflashing & Reprogramming Tools

In the first half of 2014, NHTSA has issued more than 15 recalls where the fix was to reflash a module on a vehicle. In the same time frame, more than 100 TSBs have also been issued where the solution is to reflash a module. These recalls and TSBs...

Read more...

Pulling Codes: An Advanced Misfire Story The Story of P0301

This article will document code P0301 — Misfire Activity on Cylinder No. 1 — a code many of you have run into, but sometimes we have case studies that are worthy of mention. Our subject vehicle is a 2007 Mercury Mountaineer. The vehicle has...

Read more...

The Why, Where, When of TPMS Sensors

To understand any TPMS relearn procedure, you have to understand this: Sensors only transmit, they do not receive. No vehicle asks a sensor for information on how it is doing. I know you’re thinking a sensor does receive signals when the vehicle...

Read more...

Most Common Causes of Misfire Codes

A flashing check engine light and a P0301 to P0312 diagnostic trouble code (DTC) is a surefire indication that one or more cylinders are misfiring. Occasional misfires may pass unnoticed, but a steady misfire is hard to miss. The engine usually feels...

Read more...

Pattern Failures of MAF and MAP Sensors

Pattern failures are those failures that happen over and over again — and the same applies to how customers describe these failures. Customers might unknowingly give you the answer to their problem without needing to open the hood. In this article,...

Read more...

Home DriveTrain Tech Tip: Toyota Prius Master/Hybrid MIL On/DTC P3125

Print Print Email Email

Under certain driving conditions, some 2001-’02 Prius vehicles (those built before VIN JT2BK18U*20067085) may exhibit a Master, Hybrid and MIL Warning Light “on” condition where only DTC P3125, information code 287, has set in the Hybrid Vehicle Control Unit (HV ECU). Use the following procedure to identify whether the HV ECU or inverter/converter assembly should be replaced.

Note: The HV ECU is to be replaced only if the recorded information code 287 data satisfies all of the following three conditions:
• Vehicle speed is between 25-44 mph;
• Throttle opening is 60% or more; and
• Vehicle indicated speed is greater than the recorded MG2 revolutions.

If one or more of the above conditions does not apply, use the Prius Repair Manual P3125, information code 287 Fault Isolation Procedure (FIP).

Required Tools & Material:
• Toyota Diagnostic Tester Kit, P/N 01001271;
• Toyota Diagnostic Test VP414 Printer Kit, P/N 01002488;
• 12 MB Diagnostic Tester Program Card with Version 9.3a Software (or later), P/N 01002593-005; and
• Prius Automatic Trickle Charger, P/N 00002-YA122-01.
Note: Additional diagnostic tester kits, program cards or SSTs may be ordered by calling SPX/OTC at (800) 933-8335.

Diagnostic Procedure:
1. Connect the Toyota Diagnostic Tester and print the DTC P3125, Information Code 287 freeze-frame data (or store as a Techview file using the Technical Information System).

2. Check the recorded vehicle speed. Is the vehicle speed between 25-44 mph? If yes, go to Step 3. If no, refer to the repair manual.

3. Check the accelerator sensor main value. Is it 60% or more? If yes, go to Step 4. If no, refer to the repair manual.

4. Check and note the recorded MG2 revolution speed from the Info 287 freeze-frame data.

5. Perform the following calculation to convert the vehicle speed value: Multiply the vehicle speed (mph) noted in Step 2 by 57.6 (or by 36 if vehicle speed is measured in km/h) and subtract 100. Is this value greater than the recorded MG2 revolution speed recorded in Step 4?

6. Compare the MG2 revolution speed from Step 4 to the converted vehicle speed value found in Step 5. Is the vehicle speed value higher than the MG2 revolution speed? If yes, replace the HV ECU. If not, refer to the repair manual.

Figure 1

Repair Procedure:
a. Removal and Replacement of the HV ECU.
Note: Refer to Fig. 1 and the following instructions to remove and replace the HV ECU:
1. Turn the ignition key on, push the radio power button and the audio button. Record the radio presets. Turn off all lights and accessories.

2. Turn the ignition key off and remove the key.

3. Remove the auxiliary battery cover. See Fig. 2.

4. Disconnect the negative terminal from the auxiliary battery. To prevent damage to the battery terminal, loosen the cable nut and raise the terminal straight up without twisting or prying the cable.

5. Remove the R/F door scuff plate and cowl side trim. See Fig. 1.

6. Fold the carpet back toward the passenger seat.

7. Unbolt and remove the ECU Bracket. See Fig. 1.

8. Unbolt and remove the HV ECU. Carefully remove the wire harness protector and unplug the electrical connectors from the HV ECU. Peel the (plastic) ECU cover off the HV ECU. See Fig. 1.

9. Unscrew and remove the HV ECU mounting brackets.

Figure 2

10. Screw the mounting brackets onto the new HV ECU. Install the (plastic) ECU cover.

11. Carefully plug each electrical connector and install the wire harness protector.

12. Install the HV ECU and torque the mounting nuts.
Torque: 52 in.-lbf. (6.0 Nm, 60 kgf.cm).

13. Install the ECU Bracket. Torque the mounting bolts and nuts.
Torque: 52 in.-lbf. (6.0 Nm, 60 kgf.cm).

14. Roll out the carpet and install the front door scuff plate and cowl side trim.

15. Connect the negative (-) battery terminal and tighten the cable nut.
Torque: 52 in.-lbf. (6.0 Nm, 60 kgf.cm).

16. Remove the positive (+) battery terminal cover.

17. Connect the 12-volt Prius Automatic Trickle Charger SST (P/N 00002-YA122-01) to the auxiliary battery. Connect the red charger clamp to the positive (+) terminal and the black charger clamp to the negative (-) battery terminal.

18. Plug the charger into a grounded 110V nominal outlet and verify the red “POWER” light is on. Push the charger current toggle switch to the 10-amp position. Ensure the yellow “CHARGING” light is on.

HV Immobilizer Key Code Registration Procedure:
1. Ensure the parking brake is applied and the running mode selector lever is in “P.”

2. Insert the ignition key and turn the ignition switch to the “ON” position. Leave the vehicle in this condition for at least 30 minutes.

3. After a minimum of 30 minutes has elapsed, turn the ignition key “OFF.”

4. Unplug the charger from the 110V outlet. Remove the red and black charger clamps from the battery.

5. Install the battery positive (+) terminal cover.

6. Install the auxiliary battery cover.

Figure 3

7. Depress the brake pedal, and turn and hold the ignition switch to “START” until the green “READY” indicator light remains on and steady. Then release the ignition key. See Fig. 3.

8. Ensure no trouble lights are illuminated on the Instrument panel or Multi-Information Display (MID).

9. Reset all recorded radio stations.

10. Reset the clock to the current time.

Courtesy of Mitchell 1.

For more information on Mitchell 1 products and services, automotive professionals can log onto the company’s website at www.mitchell1.com.

 

The following two tabs change content below.

Brake and Front End Staff

Latest articles from our other sites:

Veyance Technologies Launches The 'Art Of Silence' Campaign

Veyance Technologies, manufacturer of Goodyear Engineered Products and Gatorback belts, has launched the "Art of Silence" campaign, a marketing initiative that highlights the company’s continuous innovation...More

Remy Adds Delco Remy 38SI To Its High-Output Alternator Portfolio

Remy International has announced the launch of the Delco Remy 38SI, its latest high-output alternator. With this high-efficiency, mid-range amperage alternator, Remy offers customers a comprehensive portfolio...More

Internal Engine Oil Consumption Diagnostics

Due to the variables in engine design and ­operating conditions, internal engine oil ­consumption complaints are often the most difficult to solve. In some cases, oil consumption might be more severe...More

Hyundai Fuel System, Emissions Diagnostics

Hyundai has done a good job of improving its ­offerings over the years from both an aesthetic and mechanical viewpoint. Complemented by a strong warranty and good value, the carmaker has been able to...More

OTC Releases Smart Battery Tester

OTC has launched the 3200 Smart Battery Tester, offering near-instant battery, charging and starting system test results with a technician’s iOS or Android device. The tester clips onto a battery’s...More

Ernst Offers Socket Boss Universal Twist Lock Socket Tray

Versatility is a must for organizing any socket set. Capitalize on maximum configuration possibilities with the new Universal Twist-Lock Socket Tray from Ernst. Individual rails can be removed or switched...More

Hyundai: Engine Oil Pump Replacement Guidelines During Engine Replacement

Applicable Vehicles: All models Follow the guidelines outlined in this bulletin to install a new oil pump after an internal engine repair or engine short block replacement. Note: A new or remanufactured...More

The Why, Where, When of TPMS Sensors

To understand any TPMS relearn procedure, you have to understand this: Sensors only transmit, they do not receive. No vehicle asks a sensor for information on how it is doing. I know you’re thinking...More