31.1 SPN 132/FMI1
This code typically means the air mass flow is too low.
Low Air Mass Flow Check
Check as follows:
1. Check for multiple codes.
[a] If any other fault codes are present, repair them first.
[b] If only 132/1 is present, go to the next step.
2.Perform pressure check/visual inspection of the following and repair as necessary.
□ Plugged inlet air filters
□ Charge air cooler leaks
□ Leaking intake manifold
□ Exhaust leaks/plugging