Tech Tip: Honda Engine Won’t Start? Check for Loose Alternator Bolts – UnderhoodService

Main Navigation

Advertisement
Social Connect
Resources
Our Brand Family
Underhood Service Logo
Technical resources to help diagnose and repair engine-related service issues.
Electronic

Tech Tip: Honda Engine Won’t Start? Check for Loose Alternator Bolts

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.

Underhood Service Staff Writers
By Underhood Service Staff Writers
Published:

Applies to: 2001-’04 Honda Civic

Related Articles

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.

You May Also Like

External Engine

Alternator Testing For No Charge Conditions

Many alternator problems turn out to be nothing more than a bad connection at the alternator or a bad wiring harness.

Andrew Markel
By Andrew Markel
Andrew Markel is the director of content for Underhood Service magazine. He has been with Babcox Media for 20 years. He is a technician and former service writer and holds several automotive certifications from ASE and ­aftermarket manufacturers.
Published:

If only battery voltage is present at the battery on a running engine, does this mean the alternator is “bad?” No, it does not. It only means that the alternator is not charging, but does not reveal why. Therefore, it does not point to a faulty alternator. All too often, the alternator is condemned by technicians due to this test alone. The cause could instead be a module that distributes the power to the vehicle and regulates the alternator.

Read Full Article

More Electronic Posts
ECM Damage

Engineers have devised two strategies that can be called the “immune system” for the electrical system.

By Underhood Service Staff Writers
Voltage Drop Testing

The measurement of voltage is like the speed of the traffic.

By Andrew Markel
Spark Plug Fouling

Understanding why spark plugs get dirty.

By Andrew Markel
Understanding Stop/Start Charging and Starting Systems

The problem may not have been caused by a complicated reason, something simple may have caused the system not to work.

By Andrew Markel

Other Posts

Caring For AGM And Flooded Car Batteries

Faulty battery cables, if loose, corroded, or damaged, can lead to power drainage.

By Underhood Service Staff Writers
Power Window Regulator and Motor Service

Power windows are great as long as they roll up and down when commanded to do so.

By Andrew Markel
Battery Management Means Knowing How It Ages

The battery may be fully charged, but you also need to measure how low the voltages go while the engine is cranking.

By Andrew Markel
Understanding Coolants

All-season coolant used inorganic acid technology and worked great for almost 30 years.

By Andrew Markel