Question about 1991 Volvo 740
I would like to know the codes and meanings of the codes for my check engine light
Hi there, the 2-2-1 is a oxygen sensor code, and the 3-2-1 is a cold start valve code, cold start valve is controlled by the radio supression relay, (located by the coolant bottle, closest to the passenger side) the oxygen sensor is powered by the fuel injection relay (or the fuel pump relay) but on the contrary, the supression relay is powered by fuel pump relay. just food for thought, i have a 90 740 non turbo and just got done battling one of the worst inttermittant no start porblem with mine, i too had those two codes, i had some loose wires at the supression relay,.i unplugged the connector, took a dental pick and tightened the conectors in the male end, put it back together and made sure to take that same pick and push all of those wires into the connector, ( there lyed my prob) i could actually start the car, walk around, and move the relay and got the car to kill, i pushed those wires in real quick and the car came back to life. after getting that wrapped up i still had a 2-2-1 code, i drove the car for 20min and the code cleared itself. also you can try putting a couple small holes in the sides of the relay case. this helps vent some heat, those relays are natorious for overheating.
Posted on Mar 10, 2009
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Posted on Jan 02, 2017
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