Fault Code 16

Synopsis

Description: Loss of battery voltage detected with engine running
Power loss light: On
Limp-in mode: 25% alternator field coil duty cycle

Possible Causes

Blown fusible link to power module (or SMEC) - Check the only white fusible link (may look grey if dirty) by tugging on it. A good link will feel solid while a blown link will stretch like a rubber band. It is the white link on the two-link circuit (not the four or five link circuit). This link supplies power to the ASD relay and the voltage sense input on the logic module (may be accompanied by a code 42). See the Fusible Links page for more details.

Bad connection or wiring - Check the wiring and connections between the alternator and the battery, power module and the alternator field coil, and the voltage sense line through the power and logic modules.

Alternator failure or bad voltage regulator circuit - See the Diagnosing Your Charging System page.

Diagnostic Method

Trigger Parameters

- 60 seconds after engine startup
- Voltage sense input is below 8.5V

Results If Component Fails

If the voltage sense input is between 4V and 8.5V, the logic module will full-field (100% duty cycle) the alternator field coil for 20 seconds. If the voltage sense input is still below 8.5V, the system enters limp-in mode, the power loss light is turned on, a fault code 16 is stored, and the alternator field coil driver will enter a fixed, 25% duty cycle.

If the voltage sense input is below 4V, the system enters limp-in mode, the power loss light is turned on, and a fault code 16 is stored. The alternator field coil driver will enter a fixed, 25% duty cycle to prevent overcharging of the battery, but allow the vehicle to operate.

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This page is maintained by Russell W. Knize and was last updated 08/28/98. Comments? Questions? Send email.