Here is the code list from the Chilton manual for 1.6 liter MFI and TFI engines through the 1995 models:
12 - normal/end of coding sequence
13 - O2 sensor
14, 15 - coolant temp sensor
21, 22 - throttle position sensor
23, 25 - intake air temp sensor
24 - vehicle speed sensor
31, 32 - manifold air pressure sensor (8 valve)
33, 34 - mass airflow sensor (16 valve)
41 - ignition fail-safe
42 - camshaft position sensor
44, 45 - TPS idle switch
51 - EGR system
52 - fuel system (code not used on 8 valve)
53 - spec of ECM ("ground circuit" on 8 valve)
I'm not sure what the last three (51, 52, 53) mean. On the 16 valve engines, the book says they apply to 1994 USA spec and 1995 vehicles only. I got a code 51 once on my '94 8 valve when the EGR temperature sensor was disconnected because that tells the ECU if the EGR isn't working. The OBD2 control system was applicable starting with the '96 models.
The 8 valve TFI engines traded codes 31 and 32 (MAP sensor) for codes 33 and 34 (MAF sensor). There was no code 52. Code 53 was for a ground circuit. Otherwise, the lists are the same.
Don, y'all
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