1G Troubleshooting methodology query: On codes from ECU 4G37

[ohjunkitswindy]

Explanation:

http://www.dsmtuners.com/threads/1g-code-reader-cel-code-reader.319844/

I found this thread and I actually performed the buzzer method, instead of the led. Spot on advice.

I counted 13,15,21 and 25 as codes on my car and from that thread I have this:

13. Intake Air Temperature Sensor

15. Motor Position Sensor

21. Engine Coolant Temperature Sensor

25. Barometric Pressure Sensor​

Query:

1.) Motor position sensor: Is this the throttle position sensor, located on the intake manifold?
2.) I checked my Haynes manual: No idea where the Baro and Intake air temp sensor is located. ( Is/are these integrated with the MAF? ) I half expect the IAC to be on the intake.

Methodology check:

3.) If the result of question 2 is MAF, then what is the probability that a vacuum leak could cause incorrect readings on multiple instruments? Do these instruments typically falter when in the presence of a vacuum leak, or is the ECU capable of deriving a status of a sensor, or a simple logical check against an expected value? In other words, does the ECU recognize the status of a sensor, and an out of specification reading on a sensor? Can the ECU signal a fault condition, without assuming the sensor is at fault?

Thanks for your time.

 

[pauleyman]

The maf codes are probably because the car was ran without the maf plugged in. Rare to see multiple sensors fail. Reread the codes. I would expect to see three maf codes. You may have misread one.code 15 is a 1.8 only code and no its not throttle position. Ecu has no idea if a sensor is bad. Just knows a condition in a circuit. Could be sensor, wirimg, plug or ecu itself.

 

[ohjunkitswindy]

Just a follow up for future folks search the forums on the 1.8 Saturn Engine

The MAF contains the Air Intake Temperature Sensor, and the Barometric Pressure sensor, along with the Mass air flow sensor.

The motor position sensor is embedded within the distributor, so you have not choice, but to fully replace the distributor.

 

[pauleyman]

Just a follow up for future folks search the forums on the 1.8 Saturn Engine

The MAF contains the Air Intake Temperature Sensor, and the Barometric Pressure sensor, along with the Mass air flow sensor.

The motor position sensor is embedded within the distributor, so you have not choice, but to fully replace the distributor.

Maybe I should've stated that. Thats why i expected three codes because all three are contained by the one plug. Same on 4g63 cars.