Fuel/Hybrid System - MIL ON/DTC's P3101/P3190/P3191
T-SB-0180-09Rev1
June 17, 2009
MIL "ON" DTC P3101, P3190 and/or P3191
Service Category
Engine/Hybrid System
Section
Hybrid/Battery Control System
Market
USA
Applicability
TSB REVISION NOTICE
^ August 27, 2009 Rev1:
^ The Warranty Information section has been updated.
^ Repair Procedure 3 has been removed from the bulletin. Any previous printed versions of this service bulletin should be discarded.
TSB SUPERSESSION NOTICE
The information contained in this TSB supersedes TSB No. EG011-03.
^ The following sections have been updated: Production Change Information, Warranty Information, Required Tools & Equipment, Diagnostic Procedure.
^ Parts Information has been removed.
^ Overview and Repair Procedure sections have been added.
TSB No. EG011-03 is Obsolete and any printed versions should be discarded. Be sure to review the entire content of this service bulletin before proceeding.
Introduction
Some 2001 - 2003 model year Prius vehicles may exhibit a MIL "ON" condition if an abnormally low engine power output or failure to start has been detected during a particular THS drive cycle.
The following DTCs may be recorded:
1. After turning the ignition key to "START", the engine cranks and the "Ready" light will turn ON:
P3191 & P3101 with Information Code 205 may set in the engine ECM and HV ECU.
2. After Ready "ON" has occurred and after transitioning from an electric drive mode to one where the engine power is required:
P3190 & P3101 with Information Code 204 may set in the engine ECM and HV ECU.
Production Change Information
Warranty Information
APPLICABLE WARRANTY
^ This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect for 36 months or 36,000 miles, whichever occurs first, from the vehicle's in-service date.
^ For California specification vehicles sold, registered, and operated in California, Massachusetts, or Vermont, this repair is covered under the California Emission Warranty for 84 months or 70,000 miles, whichever occurs first, from the vehicle's in-service date.
^ For vehicles outside the Toyota Federal Emission Warranty or California Emission Warranty, refer to Warranty Policy Bulletin, "Customer Support Program - Warranty Enhancement for Specific Malfunction Indicator Light (MIL) "ON" Diagnostic Code on Certain 2001 through 2003 Model Year Prius Vehicles".
^ Warranty application is limited to occurrence of the specified condition described in this bulletin.
Required Tools & Equipment
Overview
The internal combustion engine in the THS system has the same fundamental operation requirements as a conventional powertrain vehicle. Issues relating to lack of maintenance fuel quality or delivery ignition system or mechanical issues such as low compression can all be possible causes of No Start or Poor Power DTC(s). Eliminate other possible causes prior to performing the detailed diagnostic procedure that follows the general trouble areas.
HINT
^ The hybrid system normally cranks the engine at 800+ rpm during starting. As a result, the engine may sound like it is running for 5 - 10 seconds then shutting off. If this occurs, DTC P3191 may set after cranking indicating that the engine did not start.
^ If the engine is NOT starting, verify as many causes at one time. Repeated cranking of the engine can deplete the HV battery.
General Trouble Areas
Air induction system (example: restricted air intake system/dirty air filter)
HINT
Check for debris lodged in the Mass Air Flow (MAF) meter. To diagnose this condition, you MUST REMOVE the MAF and inspect the 2 sensing elements inside the cavity. Clean with compressed air even if nothing is visibly contaminating the sensor. Debris may be trapped in the cavity even though it cannot be seen (Figure 1).
^ Fuel quality and level (refer to the Owner's Manual for recommendations)
NOTICE
If incorrect fuel or contamination is found, drain and flush the fuel system - including the fuel rail - BEFORE attempting to start the engine.
Problems with fuel can be difficult to identify. Follow these basic fuel tips:
^ Verify if the DTC condition occurred immediately after a refuel.
^ Diesel in the fuel can leave an oily residue after evaporation.
^ High concentrations of alcohol such as E85 fuel will have a very clear color and may leave an alcohol odor after evaporation.
^ If fuel contamination is suspected and no other problems are found, it may be helpful to drain the fuel system and add known good fuel.
^ To verify if a vehicle ran out of fuel, check the HV-ECU FFD for P3101 information code 204 or 205 "Exclusive Information 3" Data. If Exclusive Information 3 value is 1, then the system detected an "out of fuel" condition. (See Figure 2.)
^ Fuel injection system
^ Ignition system (example: worn or dirty spark plugs)
^ Poor engine compression
^ Correct engine oil viscosity and level (refer to the Owner's Manual for recommendations). If overfilled, check intake manifold for contamination.
If NO trouble is found in the general trouble areas, follow the procedures below to isolate other potential causes.
Diagnostic Procedure
Save all Freeze Frame Data (FFD) and follow the chart.
Repair Procedure 1: Clean Throttle Body
1. Remove the air cleaner assembly.
A. Disconnect the connector and clamp.
B. Disconnect the No. 1 air cleaner inlet and ventilation hose from the air cleaner assembly.
C. Remove the 2 bolts.
D. Loosen the clamp and remove the air cleaner assembly.
E. Place protective tape over the air cleaner assembly's opening to protect the MAF sensor from foreign objects.
2. Clean carbon from the throttle body assembly.
A. Using your hand rotate the link and completely open the throttle valve.
B. While holding the throttle valve open clean carbon deposits on the throttle valve and bore using a towel covered in Throttle Plate Cleaner.
CAUTION
Be careful NOT to catch your fingers or towel on the throttle valve.
NOTICE
DO NOT allow foreign objects to fall into the intake manifold.
C. If necessary use a plastic panel removal tool to remove any carbon deposits that could not be removed by wiping.
NOTICE
Be careful NOT to damage the inside of the throttle bore or valve.
3. Install the air cleaner assembly.
A. Remove the protective tape.
B. Insert the air cleaner assembly onto the throttle body assembly and tighten the clamp.
C. Install the air cleaner assembly with the 2 bolts.
Torque: 7.0 N*m (71 kgf*cm, 62 in*lbf)
D. Connect the No.1 air cleaner inlet and ventilation hose to the air cleaner assembly.
E. Connect the connector and clamp.
Make sure NO debris falls into the throttle body side of the air cleaner or MAF sensor, or DTC P3191 (Engine Does Not Start) may occur.
4. Clear the DTC(s). Ready "ON" the vehicle and verify if the DTC(s) reset.
NOTE
Make sure FFD has been saved before clearing codes.
Do the DTC(s) return?
^ YES - If any DTC(s) other than P3101, P3190 & P3191 are present, follow the applicable Diagnostic Chart for each stored DTC in the applicable Repair Manual.
After correcting other DTC(s), re-evaluate the "No Start" condition. If only "No Start" DTC(s) reoccur, proceed to Repair Procedure 2.
NO - Repair is complete.
Repair Procedure 2: Inspect Fuel Pressure
Check fuel pump operation.
Refer to TIS applicable model year Prius Repair Manual:
2001 / 2002 / 2003 Prius, Engine/Hybrid System - Fuel System - "Fuel Pump: On-Vehicle Inspection"
Connect a fuel pressure gauge to confirm the following:
^ Fuel pressure is more than 43 psi (294 KPa) at idle (1000 rpm).
^ Fuel pressure does not decrease to 0 psi (0 KPa) 5 minutes after the engine is shut OFF.
^ There is NO abnormal fuel pressure needle fluctuation while idling or driving. Does the fuel pressure pass the above specifications?
^ YES - Refer to the General Trouble Areas in this TSB for alternative causes.
^ NO - Refer to the Repair Manual for additional fuel system diagnostics.
NOTE
If fuel pressure is found to be within specifications, DO NOT replace the fuel tank assembly.