Hi, I can't resolve these codes after running KOER (warm engine), even after swapping in a spare F1ZF-AB ECU.
Start with 85 canister purge solenoid. Solenoid is not fauty, switches with 12v to ground test. There is 12v to the solenoid (key on) which the ECU should switch to ground when engine condition is met (don't know specific condition). Return wire to pin 31 has continuity. Connected trouble light to solenoid connector leads and drove around, bulb never lit. Makes me think ECU has not determined switching condition has been met. Or ECU not grounded, but would car run without ground?
Move to code 21: engine coolant temp sensor out of range. Replaced coolant sensor and checked ohm resistance for old and new sensors, seems close to chart someone published previously (see image attached). Engine cooling fan switches on after extended idle. Checked continuity of wire from connector to pin #7. Will check voltages at sensor today. Clearly the ECU recognizes sensor voltage change to switch on coolant fan. Have WBO2 to install to check whether O2 sensor is switching to closed loop, waiting on AEM to replace my faulty display.
Finally code 53: Throttle Position sensor too high . My TPS is 0.865 volts. From what I've read, this is in range, i.e. does not exceed 1.0v. Checked reference voltage is 5v, checked ground lead to battery negative post is 0.00 ohms.
So honestly, I can't see what's at fault, hence why I just swapped in a spare ECU to test. Otherwise car run good, for what it is. Has me scratching my head. Thanks for any help.
Start with 85 canister purge solenoid. Solenoid is not fauty, switches with 12v to ground test. There is 12v to the solenoid (key on) which the ECU should switch to ground when engine condition is met (don't know specific condition). Return wire to pin 31 has continuity. Connected trouble light to solenoid connector leads and drove around, bulb never lit. Makes me think ECU has not determined switching condition has been met. Or ECU not grounded, but would car run without ground?
Move to code 21: engine coolant temp sensor out of range. Replaced coolant sensor and checked ohm resistance for old and new sensors, seems close to chart someone published previously (see image attached). Engine cooling fan switches on after extended idle. Checked continuity of wire from connector to pin #7. Will check voltages at sensor today. Clearly the ECU recognizes sensor voltage change to switch on coolant fan. Have WBO2 to install to check whether O2 sensor is switching to closed loop, waiting on AEM to replace my faulty display.
Finally code 53: Throttle Position sensor too high . My TPS is 0.865 volts. From what I've read, this is in range, i.e. does not exceed 1.0v. Checked reference voltage is 5v, checked ground lead to battery negative post is 0.00 ohms.
So honestly, I can't see what's at fault, hence why I just swapped in a spare ECU to test. Otherwise car run good, for what it is. Has me scratching my head. Thanks for any help.



