Several times-----------

My daughters Accord didnt start after work...she gets iff at 11:30 am. The car is hot inside. Turns over but will not start. I told her to look at the dash and tell me if the green light (for keu imobilizer) cpmes on.

After it so,eti,es starting amd someti,ed not dhe started looking amd whenever it wouldent start (turns over OK) she said the green light on dash never came on. I thought may be the immobilizer/ key chip wasn't working.

Long story short it was the PGMFI relay. I thougt that relay was just for the fuel pump, but it also sends power to the ECM / imobolizer. Replaced it during a hot part of the day when the green key light would not come on and it immefiately fixed the issue.

Relay is under the dash near your left foot up above. -- It is comonly called the fuel pump relay...or that is what I thought that was all it did. - It also sends voltage to the ecm for the chipped key imobilizer ckt.

Hope this helps someone with reoccuring no start issues - if the green light for the key doesn't come on, especially when the interrior of the car is hot.

PGMFI Relay.

 

The PGM FI relay is a common problem on accords from the 90's through 2002. The 03 used a different relay setup. That main relay is really two relays in one unit, so it is can fail in a differnt way where the immobilizer would still get power.

The cause is that a solder joint on the circuit board gets weak over time and cracks due to heat/cooling cycles. If you have the old relay, you can look at the joints to see the issue. Resoldering the damaged solder joint(s) also fixes this issue. Youtube has videos showing this as well. You can fix the old relay and keep as a spare if you still have it.

 

You are correct. after replacing the relay i opened the old one and there is an obvious bad solder juint on one of the relays. I'll keep it and may resolder it, but just wanted to post the fix for the problem as it's very easy to get caught up in the imobolizer/key chip reader replacement which is much harder than replacing the PGM FI relay.

I thought the relay was just for the fuel sys. Glad i kept looking on the web and asking my daughter to look for the green light when it wouldn't start.

 

The reason you might not see immobilizer is the 90-97 accords don't have immobilizers. I didn't realize the main relay also powered the immobilizer in the 98-02 accords, so that is a great catch.

I just want future folks reading this wiht a crank/no-start to undertand that an immobilizer light turning on doesn't necessarily mean the main relay is good, because the main relay is two relays in one component, so the other relay could fail and cause the car to not start.