P1605

2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1605: Rough Idling
P1605 - Rough Idling

DESCRIPTION

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. Freeze frame data records engine conditions when a malfunction occurs. 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 idling is unstable due to running out of fuel.





INSPECTION PROCEDURE

HINT
- The following inspection procedure is provided as an example of one possible troubleshooting procedure for this DTC. As it is difficult to diagnose what malfunction is causing low engine speed problems, DTC P1605 was established so that freeze frame data could be used in the diagnosis of the problem when there are no DTCs stored for specific components, circuits and systems. As DTC P1605 can be stored as a result of certain driving conditions even when there is no malfunction, if the DTC is output but the customer reports that there was no problem, clear the DTC without performing any troubleshooting and return the vehicle to the customer.
- If any other DTCs are output, perform troubleshooting for those DTCs first.
- 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.)
- Read freeze frame data using the Techstream. Freeze frame data records engine conditions when a malfunction occurs.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1605)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read DTCs.

Result

Result:

HINT
If any DTCs other than P1605 are output, troubleshoot those DTCs first.

B -- GO TO DTC CHART Engine Control System - SFI System
A -- Continue to next step.

2. CHECK FREEZE FRAME DATA

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored Freeze Frame Data.

(e) Confirm the freeze frame data that the engine was cold or warm.

Freeze Frame Data

Freeze Frame Data:

(f) Confirm the freeze frame data for the engine idling condition.

Freeze Frame Data

Freeze Frame Data:

(g) Confirm the freeze frame data for the EVAP system operation.

Freeze Frame Data

Freeze Frame Data:

(h) Confirm the freeze frame data for the ISC.

Freeze Frame Data

Freeze Frame Data:

(i) Confirm the freeze frame data for the engine load and electrical load.

Freeze Frame Data

Freeze Frame Data:

(j) Referring to the freeze frame data items above, try to operate the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred.

(k) Confirm the data (Data List items) at this time and compare the data with the freeze frame data Data List / Active List.

(l) Conduct malfunctioning parts identification.

Result

Result:

B -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

A -- REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA