Part 1
1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1603, P1605: Engine Stall History
P1605 - Rough Idling
DESCRIPTION
P1603
After starting the engine, this DTC is stored when the engine stops without the engine switch being operated.
Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
It is necessary to check if the vehicle has run out of fuel before performing troubleshooting, as this DTC is also stored when the engine stalls due to running out of fuel.
P1605
This DTC is stored if the engine speed drops below the set speed.
Using the Techstream, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when idling is unstable due to running out of fuel.
1. Reference waveforms showing a normal cold engine start
2. Reference waveforms showing a normal warm engine start
3. Reference waveforms showing an engine stop after normal idling
4. Reference values when there is an air leak in the intake system during rough idling
Freeze Frame Data P1605 Rough Idling
INSPECTION PROCEDURE
HINT
- In contrast to normal malfunction diagnosis for components, circuits and systems, DTCs P1603 and P1605 are used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as engine stall.
As these DTCs can be stored as a result of certain user actions, even if these DTCs are output, if the customer makes no mention of problems, clear these DTCs without performing any troubleshooting and return the vehicle to the customer.
- If any other DTCs are output, perform troubleshooting for those DTCs first.
- Use any information from the customer problem analysis about the condition of the vehicle at the time when the problem occurred (how the engine stopped, conditions when the engine was restarted, etc.) as a reference.
- Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. This information can be useful when troubleshooting.
- When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data Freeze Frame Data.
- When DTC P1603 (Engine Stall History) is stored, DTC P1605 (Rough Idling) is also stored. When confirming freeze frame data, check DTC P1605. (The ECM stores DTC P1605 first. Therefore, the 5 sets of freeze frame data can be confirmed through DTC P1605, enabling the technician to obtain more information.)
- When confirming freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
- Try to operate the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and the data when the engine is idling (engine warmed up, no load, and shift lever in P or N) and compare these data with the freeze frame data.
- Inspections should take into account the fact that the malfunction may not have reoccurred and place emphasis on checking the vehicle conditions present at the time when the malfunction occurred.
- When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.
Inspection flow:
Using freeze frame data, narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred.
P1603:
1:
- If the engine stalled when the intake air volume was low (during idling or deceleration), there may be a decrease in torque due to an incorrect air-fuel ratio, etc.
- If the engine stalled when the intake air volume was high (during driving or acceleration), there may be a major malfunction such as continuous misfire due to ignition stoppage, fuel injection stoppage, etc. and the torque drops to zero.
2:
- If the engine speed decreased slowly, there may have been a decrease in torque due to an air-fuel ratio that was incorrect (by approximately 20 to 30%), etc.
- If the engine speed decreased rapidly, there may have been a malfunction such as when the engine misfires almost continuously due to ignition stoppage, fuel injection stoppage, etc., or when the external load increases due to an external part malfunctioning.
3:
- If the air-fuel ratio is abnormal, there may have been an intake air leak, sensor malfunction, or fuel supply problem.
- If the vehicle was normal, the air volume may have been insufficient, or the ignition timing may have been incorrect.
P1603 inspection flow: Narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred (freeze frame data).
P1605:
1:
- If the engine speed decreased slowly, there may have been a decrease in torque due to an air-fuel ratio that was incorrect (by approximately 20 to 30%), etc.
- If the engine speed decreased rapidly, there may have been a malfunction such as when the engine misfires almost continuously due to ignition stoppage, fuel injection stoppage, etc., or when the external load increases due to an external part malfunctioning.
2:
- If the air-fuel ratio is abnormal, there may have been an intake air leak, sensor malfunction, or fuel supply problem.
- If the vehicle was normal, the air volume may have been insufficient, or the ignition timing may have been incorrect.
P1605 inspection flow: Narrow down the parts to be inspected according to the vehicle conditions at the time when the malfunction occurred (freeze frame data).
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1603 AND/OR P1605)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
B -- GO TO DTC CHART SFI System
A -- Continue to next step.
2. READ FREEZE FRAME DATA
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.
Result:
HINT
- *1: A rapid decrease in engine speed may have been caused by an electrical malfunction in the shared wiring of all or multiple cylinders, an increase in load from external parts, etc. The engine speed is considered to have decreased rapidly if either of the following conditions apply.
Otherwise, the engine speed is considered to have decreased slowly.
(1) In the freeze frame data, the decrease in engine speed from #3 to #5 is 400 rpm or more.
(2) In the freeze frame data, the engine speed at #5 is 120 rpm or less.
- If the vehicle speed is 9.3 mph (15 km/h) or less and the difference between engine speed and SPD (NT) is 100 rpm or less, inspect the automatic transmission. (Depending on the rate of vehicle deceleration, the engine speed may have decreased due to the A/T lock-up release being late.)
- *2: When a DTC is stored, feedback compensation increases because the air-fuel ratio is determined to be lean.
- *3: When a DTC is stored, feedback compensation decreases because the air-fuel ratio is determined to be rich.
- *4: This item should be checked when DTC P1603 is output. If is not necessary to check this when only P1605 is output.
E -- READ FREEZE FRAME DATA
D -- CHECK HARNESS AND CONNECTOR (FUEL INJECTOR FOR PORT INJECTION POWER SOURCE)
C -- READ FREEZE FRAME DATA
B -- READ FREEZE FRAME DATA
A -- Continue to next step.
3. CHECK INTAKE SYSTEM
(a) Check for air suction in the intake system [vacuum hose disconnection, cracks, gaskets, etc.].
HINT
- If the accelerator pedal is released after racing the engine, the inspection is easier to perform because the vacuum inside the intake pipes increases and the air suction noise becomes louder.
- If Short FT and Long FT are largely different from the normal values when idling (the intake air volume is small) and almost the same as the normal values when racing the engine (the intake air volume is high), air leakage may be present.
OK:
There is no air suction.
NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.
4. CHECK PURGE VSV
(a) Disconnect the purge hose (on the canister side) of the purge VSV.
(b) Start the engine.
(c) Idle the engine.
(d) Disconnect the connector of the purge VSV.
(e) Check if air flows through the purge VSV.
OK:
Air does not flow.
(f) Connect the connector of the purge VSV.
(g) Connect the purge hose of the purge VSV.
HINT
When this inspection is performed, the MIL may illuminate. After finishing the inspection, check and clear DTCs Reading and Clearing Diagnostic Trouble Codes.
NG -- INSPECT PURGE VSV Testing and Inspection
OK -- Continue to next step.
5. READ FREEZE FRAME DATA
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.
Result:
HINT
- Try to operate the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and the data when the engine is idling (engine warmed up, no load, and shift lever in P or N) and compare these data with the freeze frame data.
- *1: If the mass air flow meter is malfunctioning and incorrectly measures the intake air volume to be less than the actual intake air volume, the freeze frame data will show a low Calculate Load value.
- *2: If the air fuel ratio sensor is malfunctioning and constantly outputs a value indicating the air-fuel ratio is lean, the actual air-fuel ratio will become rich and the engine may stall.
C -- READ FREEZE FRAME DATA
B -- PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)
A -- Continue to next step.
6. CHECK MASS AIR FLOW METER
(a) Remove the mass air flow meter.
(b) Check for foreign matter in the air flow passage of the mass air flow meter.
Result:
(c) Install the mass air flow meter.
HINT
Even if the results are normal, the mass air flow meter may have been malfunctioning. Continue this inspection procedure until step 22, and if there are no problems with other parts, replace the mass air flow meter (refer to step 55).
B -- READ FREEZE FRAME DATA
A -- REPLACE MASS AIR FLOW METER Removal
7. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Start the engine, turn off all accessory switches and warm up the engine until the engine coolant temperature stabilizes.
(d) Idle the engine.
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Data List / AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2.
(g) Read the output voltage from the air fuel ratio sensor when increasing and decreasing the fuel injection volume.
Standard:
Result:
HINT
- The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
- Even if the results are normal, the air fuel ratio sensor may have been malfunctioning. Continue this inspection procedure until step 22, and if there are no problems with other parts, replace the air fuel ratio sensor (refer to step 55).
B -- READ FREEZE FRAME DATA
A -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR POWER SOURCE)
(a) Disconnect the air fuel ratio sensor connector.
(b) Turn the engine switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
HINT
- Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
- Make sure there is not an excessive amount of force applied to the wire harness.
(d) Reconnect the air fuel ratio sensor connector.
NG -- CHECK AIR FUEL RATIO SENSOR POWER SOURCE CIRCUIT P0031
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)
(a) Disconnect the air fuel ratio sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
Standard Resistance (Check for Short):
HINT
- Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
- Make sure there is not an excessive amount of force applied to the wire harness.
(d) Reconnect the ECM connector.
(e) Reconnect the air fuel ratio sensor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR FUEL RATIO SENSOR Removal