I just bought my truck recently and I am having the same 4WD LOW light flash in the dash but no response at all from the hubs when I turn the switch. I also keep throwing an EGR code and my HVAC damper isn't working. Obviously, I have a vacuum leak of sorts. I've already combed through and replaced the vacuum lines associated with the EGR system and traced to the reservoir for the cab under the air filter into the cab. No luck. I thought that maybe there is a hose or connection etc that would notorious for failing and someone would know. Any suggestions?

I'm going to buy a vacuum gauge today to help me narrow it down. Ill let you know if I've found anything.

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96 XLT, Extended Cab, 4.0 Pushrod, 4WD, 5 Speed, A/C, 195k miles, K&N cold air intake, everything else stock.

What was the actual code?

Damper not working?

I don't think vacuum has anything to do with the 4x4.

Spend your money on a code reader instead of vacuum gauge?

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sent from DROID Bionic using tapatalk-2. (Ranger, 1999, reg cab, 2.5, 5 speed, 2WD) (2006, Vibe, 1ZZ, Auto, AWD)

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

The code is P0401. Insufficient EGR flow. So, the 4WD issue and the HVAC issue have nothing to do with that. But could the two be tied together?

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96 XLT, Extended Cab, 4.0 Pushrod, 4WD, 5 Speed, A/C, 195k miles, K&N cold air intake, everything else stock.

The damper is stuck on what I would say is the default position (defrost). Can't adjust the direction of air flow. E.g. vent, floor, mix, etc. Also, just tinkering in the parking lot at work today. I got the 4wd to engage. Don't know how and the only way I could dis

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Cont...... The only way I could disengage it was to put the switch in 2wd, kill the engine and restart it. Now it won't come back on and the lights in the dash are flashing in a pattern. 6 flashes about every 2 minutes.


Sorry about the erratic posts. I'm posting via smartphone and it got screwed up somehow.

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96 XLT, Extended Cab, 4.0 Pushrod, 4WD, 5 Speed, A/C, 195k miles, K&N cold air intake, everything else stock.

You probably have 3 different issues

1) when you lose vacuum to the hvac it defaults to defrost for obvious reasons

2) if you cleaned the inside of the egr valve and checked the 2 hoses to the dpfe sensor and still have the code most likely the dpfe sensor is bad easy fix.

3) there is a motor that shifts into 4wd when you hit the button. It might be the issue. Keep investigating that issue
http://www.therangerstation.com/tech...shiftmotor.htm

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VAnd my compliments to you for creating a signature. You are already smarter and more organized then 80% of the members here. You should add AC? Cab? Mileage

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2004 Ext Cab, 4WD, 4.0, Auto, 154k. (4.0 engine is out of a 2009 Ranger w/96k) ( as of 7/1/2017)

2004 Ranger, Ext Cab, 2WD, 3.0, 5 speed , 4WABS, crank windows, no cruise, Edge 116k.(6/5,2014) (SOLD).
1999 Ford Ranger, Reg Cab, 2.5, 5 speed, 2WD, no AC, 150k (SOLD).

Thanks. In the process of trying to troubleshoot the problem, I've checked and replaced all of the tubing in the EGR system and even bought a new sensor to try. Still throwing the code. How do you go about cleaning the EGR valve?

Ill definitely try cleaning the shift motor just as general maintenance but I noticed a relatively large ground cable just dangling around just "south" of the drivers side exhaust manifold while playing around with the EGR. Got too dark outside to investigate further but hopefully its the ground for the shift motor...?

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96 XLT, Extended Cab, 4.0 Pushrod, 4WD, 5 Speed, A/C, 195k miles, K&N cold air intake, everything else stock.