(M) Ignition TACH signal was erratic (module/wiring) or SPOUT circuit fault - Ignition Systems
Oxygen sensor signal (front sensor on 94 and later models).
Error Code :212 To understand the true meaning behind this DTC, let's try and break down its definition, 'Oxygen sensor signal (front sensor on 94 and later models). '. Right off the bat, we can see that this code has to do to with the vehicle's post catalyst fuel trim system, or to be more specific, the fuel itself. In the simplest of terms, this means that your powertrain control module (PCM) has detected via oxygen sensors in the exhaust system.
Track the voltage curve of accelerator pedal position sensor 1 and 2 in the engine data stream by GDS2 diagnostic tool.(show in below pic).According to the voltage curve,we found voltage signal of APP1 and APP2 difference value are not expressed in multiple relation