Applies to: 2001-’04 Honda Civic
Got a 2001-’04 Civic in your shop with any or all of these symptoms?
• The engine cranks but it won’t start.
• The MIL comes on.
• The immobilizer indicator blinks while the engine cranks.
• The HDS can’t communicate with the ECM/PCM.
Check for loose alternator bolts. If these bolts are loose for any reason such as the alternator was R&R’ed, or an accessory A/C was installed on a DX model at the dealership, the alternator can overcharge and fry the ECM/PCM.
If the alternator bolts are loose, tighten them and try restarting the engine. If the engine still won’t start, then check the ECM/PCM connector for battery voltage and ground. If you’re reading battery voltage and ground at the connector, then replace the ECM/PCM. Keep in mind, though, any ECM/PCM damage that’s caused by loose alternator bolts from A/C installation or body repair isn’t covered under warranty.
Courtesy of Honda Service News via ALLDATA.