Ch3 - Code 41, Codes 41/47 - Alternator Field (Low Charging System Output)
- Connect diagnostic readout box to engine harness connector. Connect one end of voltmeter to a good engine ground. Put system in ATM Test Mode 09. Touch other lead to each of alternator field terminals. Check voltmeter reading. If voltmeter reads zero volts at both alternator field terminals, repair J2 circuit to alternator field for an open circuit to wiring harness splice.
- If voltmeter reads battery voltage at one field terminal and is pulsating between zero and battery voltage at other terminal, check for improper alternator drive belt tightness. Check battery or alternator for normal operation. If voltmeter reads battery voltage at both field terminals, turn ignition off and unplug 14-way connector from engine control module.
- Connect voltmeter to cavity No. 14 and turn ignition on. If voltmeter reads within one volt of battery voltage, go to step 4). If voltmeter reads zero, repair Dark Green wire of cavity No. 14 of 14-way connector for an open circuit to alternator.
- Turn ignition off and separate the engine control module (SMEC) 14-way connector. Reconnect half of connector that contains cavities No. 1-7 to engine control module. Connect positive lead of analog voltmeter to cavity No. 14 in half of 14-way connector that is not connected to the SMEC. Connect negative lead of voltmeter to cavity No. 11 of same connector. Place system in ATM Test Mode 09.
- If voltmeter is pulsating between zero and 12 volts, power board is defective. Replace engine control module. If voltmeter reads zero volts, turn ignition off and unplug 60-way connector from engine control module. Connect ohmmeter between cavity No. 11 of 14-way connector and cavity No. 14 of 60-way connector. If ohmmeter shows continuity, logic board is defective. Replace engine control module. If ohmmeter is not showing continuity, repair Dark Green/Orange wire of 60-way connector for an open circuit to 14-way connector.