Bought my 1998 LX470 about a year ago and had the first signs of this issue rear it's ugly head on a camping trip not shortly after purchase. Upon inspection, I found that the connector going into the throttle level assembly w/ sensor (22060-50011) on the left side no longer had a locking tab and had worked itself loose. Used a ziptie as a temporary remedy, replaced the pigtail going into the connector and prayed that it would be the last time I saw the code P1121.
Just recently, after taking the vehicle for a 300 mile roundtrip visit to the beach, having had no issues to or from - started the vehicle Monday morning and immediate check engine light with code P1121 again. No response from the accelerator pedal until the last 10% for the drive-by-wire limp home mode.
Thinking at this point that with good wiring going in, that the throttle level assembly w/ sensor (22060-50011) was the culprit given the code - replaced it with an OE part from Toyota with no change. This led me to want to chase the throttle position sensor (89452-30140) - after searching up and down to figure out where the TPS is located, I eventually found it was located on the underside of the right side of the throttle body. Pulled the throttle body - be aware there are coolant lines going into it that will drip when pulling the entire throttle body out - as I did not see an easy way of reaching it without removal. Replaced the sensor, with the amount of grime on the exterior of the throttle body, I was able to place it in the same spot without having to do any adjustment procedures like Toyota advises to be performed (worked out for me in the long run). I would recommend cleaning the throttle valve while you have it off.
After replacement of both sensors and everything being reinstalled, still could not clear this code which I found will restrict the vehicle to it's limp home mode until cleared. Even with Toyota's techstream hooked up to the vehicle, just could not be rid of it. Read about a situation similar on ih8mud and tried disconnecting the battery overnight. Came back the next morning, started the vehicle and found no more check engine light. Monitored the throttle valve opening percentage to ensure it sat between 10-14% when closed. Test drove and no issue has returned.
Will update if anything changes but for those not looking to try their luck at a junkyard throttle body, I hope this helps.
Attached is images for the procedure from toyota for replacement of throttle body components that I used as reference for my repair.
Just recently, after taking the vehicle for a 300 mile roundtrip visit to the beach, having had no issues to or from - started the vehicle Monday morning and immediate check engine light with code P1121 again. No response from the accelerator pedal until the last 10% for the drive-by-wire limp home mode.
Thinking at this point that with good wiring going in, that the throttle level assembly w/ sensor (22060-50011) was the culprit given the code - replaced it with an OE part from Toyota with no change. This led me to want to chase the throttle position sensor (89452-30140) - after searching up and down to figure out where the TPS is located, I eventually found it was located on the underside of the right side of the throttle body. Pulled the throttle body - be aware there are coolant lines going into it that will drip when pulling the entire throttle body out - as I did not see an easy way of reaching it without removal. Replaced the sensor, with the amount of grime on the exterior of the throttle body, I was able to place it in the same spot without having to do any adjustment procedures like Toyota advises to be performed (worked out for me in the long run). I would recommend cleaning the throttle valve while you have it off.
After replacement of both sensors and everything being reinstalled, still could not clear this code which I found will restrict the vehicle to it's limp home mode until cleared. Even with Toyota's techstream hooked up to the vehicle, just could not be rid of it. Read about a situation similar on ih8mud and tried disconnecting the battery overnight. Came back the next morning, started the vehicle and found no more check engine light. Monitored the throttle valve opening percentage to ensure it sat between 10-14% when closed. Test drove and no issue has returned.
Will update if anything changes but for those not looking to try their luck at a junkyard throttle body, I hope this helps.
Attached is images for the procedure from toyota for replacement of throttle body components that I used as reference for my repair.
