I have an 98 Expy that now continously (everytime I turn the ignition on) displays an airbag code 45 which I believe is LH crash sensor not mounted to vehicle properly. This code has been coming and going for about a year and a half. The last time it did it was almost 6 months ago and I almost completely forgot about it until it came back last week. Usually it would go away the same day, but this time it has presisted for a week. I have disconneted the sensor from the harness, checked the ground to be 0 ohms resistence on the P/LG wire to the frame. I removed the sensor and cleaned up the mounting bracket to radiator core support just in case. Result equals no change, still displaying code 45. Do I have the correct description for this code number with respect to my vehicle? The sensor case is cracked and rusted, but electrically the ground appears to be in tact? There are (3) wires coming from the sensor, one is a ground, what are the other (2)? Where is the airbag diagnostic module located. Some say under the radio, others say RH kick panel? I don't just want to start tearing into stuff, but would like to check the continuity of the ground wires from the sensor connector to the module.

 

Hi guys,

I have this same airbag code on a 98 Expedition EB 4X4 with 166k on it. And noticed there were no answers to the last post. How did you resolve this, DA080682?
Is it still flashing?
Did you fix it?
Where IS the module located?

Mine was flashing airbag code 45 then somehow went to code 44. I took the RHS sensor off, antiseized the bolts and the connectors and put it back on and now the code 45 is back. 45 has been flashing for years. I read that there is a connector plug somewhere that needs to be cleaned up for this type problem. Where is it?

Please help.

 

sGreuel,

I had to replaced my left hand crash sensor and the code went away and has not returned since. The airbag control module looks for a path to ground through the sensor case to the mount (radiator core support). This is how it determines that it is mounted properly. I had good continuity from the frame to the sensor case, but did not have good continuity from the case to the ground wire. In my case, I believe the path to ground was intermittent because the case was rusty and cracked and the rivet where the ground wire attaches from the harness to the case did not have a good connection.

 

DA080682,

Do you remember which one of the wires, what color on the sensor that went to ground? Or did you just test them all until you found one close to ground?

I also wonder if when the case is not grounding there at the sensor, if you could just jumper a splice from that ground wire there to the bracket. At least to test and see if that was the problem. If that worked I could eliminate the possibility of all of the wiring.

A little history, this 1998 was a Texas car, on top of that it has been garage kept since 2000 in Southern Oklahoma. Alot of stuff on the car still has the factory paper labels. There is no rust. Sensors look brand new. It does however look to have had a repair on the left front. I am starting to wonder if maybe it has had some wiring damage there.

Thank you,]
s

 

NOTE: Circuit 620(P/LB) is riveted to the side of the LH air bag sensor case, and the case of the sensor is grounded to the vehicle at its mounting point.

The air bag diagnostic monitor measures the resistance between Pin C208-20, Circuit 620(P/LB), and the reference ground at Pin C209-t8, Circuit 649(BK/O). If a difference of more than 3.0 ohms between the ground at Pin C209-18, Circuit 649(BK/O), and the ground at Pin C208-20, Circuit 620(P/LB) is measured, the air bag diagnostic monitor will store a Diagnostic Trouble Code (DTC) B1945 in memory and flash a Lamp Fault Code (LFC) 45 on the air bag indicator. Should the difference in resistance between Pin C209-18, Circuit 649(BK/O), and Pin C208-20, Circuit 620(P/LB), be repaired or otherwise reduced to less than 3.0 ohms , the air bag diagnostic monitor will store the DTC B1945 in memory.

Possible Causes
A high resistance reading on Pin C208-20, Circuit 620(P/LB) or Pin C209-18, Circuit 649(BK/O) can be caused by:
A poor attachment of LH air bag sensor and bracket due to loose mounting, dirt, or corrosion at its mounting location.
An open or damaged wire in Circuit 620(P/LB). an open wire or loose rivet inside LH air bag sensor and bracket.
A poor reference ground at Pin C208-10, Circuit 650(BK/LB) or Pin C209-18, Circuit 649(BK/O).