I have a 2007 IS250 2wd that has been running great the last 5 years until a month ago, when my starting issue surfaced. It happened the 1st time one morning when I stepped out to go to work, tried to unlock the car door with my key fob....strangely, the car wouldn't unlock. I had to pop out the key cover and manually open the car door. I thought the battery was bad, but it measured 12.9v. Electronic buttons inside the car were found to be unresponsive (ie. can't open trunk, fuel door, lock/unlock, etc) . Anyways, I stepped on the brake and pushed the start button, the car detects the key, the dashboard lights up and dial moves; however, it doesn't crank. The car acts as if I didn't step on the brake pedal and the Engine Start button was amber, not green.
Then out of ideas, I disconnected the battery cable and waited about 15 minutes. Luckily, when I plugged the battery cables back in, the car re-initiated and the engine started. It ran perfectly fine for a couple weeks, then the same issue happened again. I disconnected and reconnected the battery to reset ECU and the car started up just fine. I operated the car to work everyday for a few weeks until it occurred again this morning. I tried to disconnect the battery and plug it back in; however, this time around it didn't work. To rule out any battery issues, I took the battery out of the car to charge it up fully and I also changed the battery in my key fob.
My troubleshooting:
1. Remote communicates (it could activate panic button), but is UNABLE to physically unlock or lock car, open truck (it does beep), etc. It's possible none of the actuators receive any power.
2. I can verify remote key code is sensed and cleared by security ECU (otherwise, it would report as "key not detected" and won't initiate ignition power).
3. No issues with main or exterior electrical power (dome light, dash lights, headlights, etc. works well).
4. Interior / Cabin electrical buttons / solenoids (lock/unlock, windows, side mirrors, trunk release, seats, radio, clock, etc) have no power and are non-functional.
5. Brake pedal remains stiff; cannot depress fully, no brake light (possibly no power to allow brake solenoid to release?); As a result, push-start button is always amber, not green.
6. I was able to resolve the issue a couple times by disconnecting battery cable to reset ECU and have the engine started, but the 3rd attempt failed; car is now disabled.
I highly suspect something relating to the ECU/immobilization system is limiting the electrical power to the essential components in the cabin (in order to start the car); however, I don't have much troubleshooting experience or equipment to go past my current findings. If you've encountered similar issues before or have more troubleshooting ideas, I would greatly appreciate your advice. Thank you.
Then out of ideas, I disconnected the battery cable and waited about 15 minutes. Luckily, when I plugged the battery cables back in, the car re-initiated and the engine started. It ran perfectly fine for a couple weeks, then the same issue happened again. I disconnected and reconnected the battery to reset ECU and the car started up just fine. I operated the car to work everyday for a few weeks until it occurred again this morning. I tried to disconnect the battery and plug it back in; however, this time around it didn't work. To rule out any battery issues, I took the battery out of the car to charge it up fully and I also changed the battery in my key fob.
My troubleshooting:
1. Remote communicates (it could activate panic button), but is UNABLE to physically unlock or lock car, open truck (it does beep), etc. It's possible none of the actuators receive any power.
2. I can verify remote key code is sensed and cleared by security ECU (otherwise, it would report as "key not detected" and won't initiate ignition power).
3. No issues with main or exterior electrical power (dome light, dash lights, headlights, etc. works well).
4. Interior / Cabin electrical buttons / solenoids (lock/unlock, windows, side mirrors, trunk release, seats, radio, clock, etc) have no power and are non-functional.
5. Brake pedal remains stiff; cannot depress fully, no brake light (possibly no power to allow brake solenoid to release?); As a result, push-start button is always amber, not green.
6. I was able to resolve the issue a couple times by disconnecting battery cable to reset ECU and have the engine started, but the 3rd attempt failed; car is now disabled.
I highly suspect something relating to the ECU/immobilization system is limiting the electrical power to the essential components in the cabin (in order to start the car); however, I don't have much troubleshooting experience or equipment to go past my current findings. If you've encountered similar issues before or have more troubleshooting ideas, I would greatly appreciate your advice. Thank you.
