My check engine light is on

80

Asked by Feb 18, 2014 at 01:24 PM about the 1994 Dodge Ram 1500 2 Dr LT 4WD Standard Cab LB

Question type: Maintenance & Repair

My check engine light is on and the codes that flash are 12 and 21. the truck idles rough
and i replaced the iac sensor thinking that was the problem. didn't fix it, and haven't gotten
around to replacing the O2 sensor just yet, but I don't think that would cause it to sputter
and almost die, or would it?

11 Answers

1,535

O2 sensors will not cause any rough idle or misfire how do you know is code 20 and 21?

1 out of 1 people think this is helpful.
80

if you do the on off on off on deal with the ignition the check engine light flashes to give you the codes that are registered. it flashes once pauses then twice and pauses making it a 12, twice pause once pause making it a 21, and then it does the twice pause once again.

1,535

If you rev the engine does it backfire?

80

no it doesn't. it did it to me today and it almost died completely and the oil pressure light started to come on. i tapped the accelerator and it went back to normal.

1,535

You mean it back fired today?

80

no it has never backfired. what i meant is it was starting to sputter on me and almost died. sorry for the confusion

1,535

Do you have a distributor?

80

If I do it is not readily accessible. I can trace my plug wires to the back of the block, but i can't really tell what they are plugging in to.

1,535

What size engine do you have?

80

it's the 5.2L V8. I am thinking maybe the TPS but my multi meter has gone MIA....

65,955

Only be concerned with the code 21. The code 12 is just telling you that the battery has been recently disconnected. Code 21 is a problem with the oxygen sensor circuit. It's shorted. You'll have to inspect the wiring going to the oxygen sensor. HTH. -Jim

Your Answer

Add photo

Related Questions

  • Check engine light 2 answers

    What is causing check engine light?

    1994 Dodge Ram 1500 2 Dr LT Standard Cab LB

    -

    Maintenance & Repair

  • why does my check engine light never come on 3 answers

    my check engine light does not come on when i start to crank my truck all other gauge lights come on anyone have any suggestion thanks i am getting a code p 1763 and p 1762 i know what these are but n...

    1998 Dodge Ram 1500

    -

    Maintenance & Repair

  • check engine light 3 answers

    i revved the engine the other day while it was still moving. I went to go start it yesterday and the check engine light came on it has never done this before. can anyone help me out? Thanks

    2006 Dodge Ram 1500 SLT Quad Cab SB 4WD

    -

    Maintenance & Repair

  • check engine light stays on 2003 1 answer

    after start up check engine light stays on

    2003 Dodge Ram 1500 SLT Quad Cab SB

    -

    Maintenance & Repair

  • why is my check engine light on? 2 answers

    my 1999 dodge ram 1500 runs great, but yesterday my check engine light came on whats up?

    1999 Dodge Ram 1500

    -

    Maintenance & Repair

Ram 1500

Looking for a Used Ram 1500 in your area?

CarGurus has 11,092 nationwide Ram 1500 listings starting at $700.

ZIP:

Search Dodge Ram 1500 Questions

Dodge Ram 1500 Experts

#1 Dan Connell
Dan Connell
Reputation 6,090
#2 pudgybear
pudgybear
Reputation 5,880
#3 dandyoun
dandyoun
Reputation 5,290
View All

Related Models For Sale

Used Ford F-150
2,178 Great Deals out of 206,277 listings starting at $1,499
Used Dodge Ram 2500
153 Great Deals out of 5,233 listings starting at $3,495
Used GMC Sierra 1500
811 Great Deals out of 67,884 listings starting at $2,484
Used Toyota Tacoma
524 Great Deals out of 40,493 listings starting at $2,495
Used Dodge Dakota
103 Great Deals out of 3,743 listings starting at $1,680
Used Ford Mustang
459 Great Deals out of 45,641 listings starting at $1,999
Used Dodge Ram 3500
92 Great Deals out of 2,169 listings starting at $4,999
Used Jeep Wrangler
271 Great Deals out of 18,084 listings starting at $2,950

Used Cars For Sale

2010 Dodge Ram 1500 For Sale
74 Great Deals out of 1,320 listings starting at $6,900
2009 Dodge Ram 1500 For Sale
44 Great Deals out of 1,007 listings starting at $3,999
2008 Dodge Ram 1500 For Sale
84 Great Deals out of 1,535 listings starting at $2,995
2007 Dodge Ram 1500 For Sale
67 Great Deals out of 1,466 listings starting at $2,800
2006 Dodge Ram 1500 For Sale
70 Great Deals out of 1,359 listings starting at $3,500

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.