2001 Corolla stalling, hesitation (1 Viewer)

[morganism]

Just gonna post this up here, so maybe i can find it again later.

This is a software problem, a firmware update could fix, but they will not roll it out.

This throws O2 sensor codes, and then cyl codes as vehicle starts to misfire.

Simple fix is to disconnect both O2 sensors in front of cat, then clear the ECS. This will cause vehicle to kick down to "basic" settings. Then reset the ECS, and drive at 55 for 10 min, then idle at side of the road, in gear, with foot on the brake for 2 minutes.


Reset Procedure

Disconnect battery neg terminal. ( or can pull the EFI #1 and ETCS fuses).

While disconnected, turn key to the ON, not start position for 2-3 min to drain the capacitor in ECU, and reset to the baseline run conditions. This will remove the CEL , or MIL, so you can set the monitor cycles by driving, and stopping to idle w foot on the brake.


Setting Cat Monitor Cycle. (portion of 23 page pdf link below.)

Catalyst Monitor not ready but no trouble codes

http://www.toyotapart.com/READINESS_MONITOR_DRIVE_PATTERNS_T-EG02-003.pdf

The cat temp sensor , and i think, a high altitude sensor, will eventually start causing problems again. When it starts "ticking" a lot, reset it again, and should be good until the next major storm blows thru, screwing up the high alt sensing.

and tech info by engine designation

Toyota Parts | Toyota Engine Families - A Comprehensive Guide

ABS light reset:

First fill the brake fluid res, then clean the ANS sensor, that is magnetic, and picks up metal shards.
Now reset the ABS light, jump the TE1, to the E1 connector at the OBD connector, KEY at ON, and start tapping the brakes, about twice a minute, at least 8 times, or 4-5 minutes.

 

[morganism]

Looks like the problem isn't a high altitude sensor, it is prob related to gas tank pressure, and she's driving uphill, thru S curves, on a day when a low pressure system is coming in. With major temp swings, it looks like it will never set.

Toyota Corolla Repair Manual: Evaporative emission control system pressure sensor - Sfi system - Diagnostics

and the temp has to be withing 13o of each other, not going to happen in the desert often...

"You have to do the COLD SOAK PROCEDURE which is getting the temp of the engine and air within 13 degrees.
Then when you start it after the 8hr soak, the test should complete in 20 minutes of driving.

we let them cool down with a fan to get the temps close and then pass all the other monitors leaving the evap INCOMPLETE, then we can smog a vehicle
BUT.... the only way we can get the EVAP to pass is if the vehicle sits for 8 hrs and the engine and air temps are within 13 degrees"

From my drive pattern PDF:
IMPORTANT:
A cold soak must be performed prior to conducting the drive pattern to complete the
Internal Pressure Readiness Monitor.
Cold Soak Procedure
1a. Start the engine and allow ECT (Coolant Temp) to reach 176F (80C) or greater.
(This can be done by letting the engine idle or by driving the vehicle.)
1b. Let the vehicle cold soak for 8 hours or until the difference between IAT (Intake
Air) and ECT (Coolant Temp) is less than 13F (7C).

Cheating Readiness Monitor? (drive cycles diagnostic on OBD2 scanner) - Toyota Tundra Forums : Tundra Solutions Forum