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PGM-FI main relay problem

Old 11-30-2006, 08:39 PM
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Join Date: Nov 2006
Posts: 1
Default PGM-FI main relay problem

this is on an 03 civic ex with the sohc 1.7 vtec. the car will start and while at idle the check engine light will blink and the pgm-fi main relay (the blue one) will click at the same time. also when this happens the idle drops like the engine missfires. it will keep doing this while at idle. it will do it at a constant rate, and after it does it 14 times the check engine light stays on and the car goes into a rough idle. if you give it some throttle it will studder and missfire and slightly rev (approx 2-3k rpm) and not raise above that because of a missfire. also the tachometer reads zero when the CEL turns on.

Where should i start looking to solve this problem? anybody have a clue as to whats going on with the car? your help is greatly appreciated.
Old 11-21-2014, 12:35 PM
VeloSi's Avatar
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Join Date: Nov 2014
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Wow I have an '02 Civic EX coupe and I am having the same exact problems just as this post! Now mine has been replaced with two new PGM FI relays and same problems persist... What can this be?
Old 11-21-2014, 03:10 PM
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Join Date: Jun 2007
Posts: 10,023

Any time the CEL comes on -- much can likely be learned by pulling the code(s). It sounds like the crank sensor or something fundamental.

The faulty relays were in 1988-1995 models. 1996 and later have a different design and a problem with the relay itself is very rare.

The ECU drives the relay. Relay clicking on and off when it shouldn't is because the ECU is doing it, in response to something.
Old 11-21-2014, 05:35 PM
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Join Date: Nov 2014
Posts: 2

I can't pull no codes with the scanner, I guess have a problem there too? Scanner reads "it cant link/connect"
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