Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Failure Mode Effects Management (FMEM)

Failure Mode Effects Management (FMEM) is an alternate system strategy in the Powertrain Control Module (PCM) that maintains vehicle operation if one or more sensor inputs fail.

When a sensor input is perceived to be out-of-limits by the PCM, an alternative strategy will be initiated.

The PCM will substitute a fixed in-limit sensor value and continue to monitor the faulty sensor input. If the faulty sensor operates within limits, the PCM will return to the normal engine running strategy.

- Key ON Engine Running Diagnostic Trouble Code (DTC) 998 will be displayed when FMEM is in effect.
- The Malfunction Indicator Lamp (MIL) will remain ON when FMEM is in effect.