Trouble Code Explanation

See CHARGING SYSTEM FAULT CODES table for charging-related faults.
Code 12 will set if battery feed to PCM has been disconnected within last 50-100 starts. PCM monitors circuit when ignition is on.
Code 41 will set if PCM output for alternator field does not respond to voltage regulator control signal. PCM monitors circuit when ignition is on.
Code 44 will set if battery temperature sense voltage goes out of range. PCM monitors circuit when ignition is on.
Code 46 will set if battery sense voltage is more than one volt above desired control voltage for more than 20 seconds. PCM monitors this signal whenever engine is running.
Code 47 will set if battery sense voltage is less than one volt below desired control voltage for more than 20 seconds, and active test indicates an alternator problem. PCM monitors this signal whenever engine speed is above 1500 RPM.

CHARGING SYSTEM FAULT CODES

Fault Code

Circuit Description

CHECK ENGINE Light On

Battery Feed To PCM

41 ⁽¹⁾

Alternator Field Control

Yes

44 ⁽¹⁾

⁽²⁾ Battery Temp. Sensor

Yes

46 ⁽¹⁾

High Battery Voltage

Yes

47 ⁽¹⁾

Low Battery Voltage

Yes

End Of Diagnostic Mode

⁽¹⁾	This code will cause limp-in mode.

⁽²⁾	Sensor is inside PCM. If faulty, replace PCM.

NOTE: Only charging system-related codes are listed here. For engine-related codes, see G - TESTS W/ CODES article in ENGINE PERFORMANCE.