Airbag code 45

[kgzak]

I have a 1998 Ford Explorer and keep getting the airbag code 45. I did a search and all I get is people saying what it is but not how to fix it. They all say it's LH Radiator Impact Sensor not mounted properly. So I have 2 questions, How do you fix it and is that Driver's side or Passenger's side?

 

[scucci]

This may help - (left hand is drivers side), (the sensor is mounted under/behind the front bumper). from the service manual:
Pinpoint Test N: LFC 45/DTC B1945 — LH Air Bag Sensor Not Mounted to Vehicle Properly

Normal Operation

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 C233-20, Circuit 620 (P/LB), and the reference ground at Pin C232-18, Circuit 570 (BK/W). If a difference of more than 3.0 ohms between the ground at Pin C232-18, Circuit 570 (BK/W), and the ground at Pin C233-20, 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 C232-18, Circuit 570 (BK/W), and Pin C233-20, 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 C233-20, Circuit 620 (P/LB) or Pin C232-18, Circuit 570 (BK/W) 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 C233-10 or Pin C232-18, Circuit 570 (BK/W).

 

[kgzak]

Okay, I measured the resistance from the case surrounding the sensor to the frame and it measured like .02 ohms. So what do you think the cause of the problem could be? I might have read it wrong, it's dark and in a hard spot to get to so I might have messed up but it looks like it should be fine. Any ideas on what to do next? Also will the airbags still go off if I get in an accident?

 

[scucci]

Okay, I measured the resistance from the case surrounding the sensor to the frame and it measured like .02 ohms. So what do you think the cause of the problem could be? I might have read it wrong, it's dark and in a hard spot to get to so I might have messed up but it looks like it should be fine. Any ideas on what to do next? Also will the airbags still go off if I get in an accident?

Possibly check the connector pins and check for a wire fault in the harness. Pink/light blue stripe wire and black/white stripe wire Maybe there is corrosion on the contacts or a break in one of those wires.

 

[kgzak]

I think I got it. I took the sensor/bracket off and cleaned it. Then I put it back on making sure it was tight. Left the battery unplugged for a while. Just took the car for a drive and no light. I am hoping it stays. Thanks for all your help!

 

[scucci]

I think I got it. I took the sensor/bracket off and cleaned it. Then I put it back on making sure it was tight. Left the battery unplugged for a while. Just took the car for a drive and no light. I am hoping it stays. Thanks for all your help!

That is great! You are becoming a top notch troubleshooter.

 

[exploder1995]

does anyone know if it is required that you replace the airbag ECU after both the drivers side and passengers airbags have deployed, will the new air bags still work if the ECU is not replaced?

 

[SteveinNC]

Fellas,
I hope its not a problem bringing an old thread back to life. I'm helping a lady I go to church with to save her some money so she can sell her 1998 Explorer Sport.
At first it had the 5 chimes when starting the vehicle and the airbag light would not light up during start up. So pulled the instrument panel and replaced the air bag warning bulb. That fixed the warning chime issue and now get a 42 code which is the left front sensor issue mentioned above. Before I go spending money on this I have a quick question:

Can I pulled on the passenger side sensor and plug it into the left front wiring and see if the code clears to tell me if the issue is in the wiring or in the sensor itself?

Any other troubleshooting issues you can think of I would appreciate it. If everyone says its ok to transfer the RF sensor to the LF for testing purposes only and assume the issue doesn't go away.... where do I get the pinout info everyone talks about?

Thanks in advance,
Steve


140311@1413 Update:
Gentleman,
I went ahead and took the front bumper off the vehicle to ease getting the passenger side sensor disconnected. I swapped the sensors (drivers side sensor is now on passenger side and vice-versa). It is still showing the 42 code after swapping sides. Do I need to clear the computer of the "old" 42 code before trying to evaluate these tests results? Or is this current 42 code definitely telling me the issue isn't in the sensor or connectors and in the drivers side wiring harness for sure?

Thanks in advance for your help!
Steve