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2000 Dodge Durango SLT 5.9L - P1899 Code: Neutral Safety Switch Failure Causes Loss of Reverse and All Gears

Model: 2000 dodge durango slt 5.9 Fault Code: P1899 Posted: 2018-03-19 10:22

I'm experiencing a P1899 diagnostic code on my 2000 Dodge Durango SLT with the 5.9L engine. This code indicates a malfunction in the Neutral Safety Switch. I recently replaced the switch because the truck wouldn't engage park, but after installation, it now only allows drive gear operation — reverse, neutral, and gears 2 and 1 are completely unresponsive. The gear indicator lights are also incorrect: they show forward positions for all gears except reverse. Additionally, when the ignition is off, the vehicle rolls forward if the emergency brake is not applied. The issue appears to be related to both hardware positioning and signal integrity from the switch to the Powertrain Control Module (PCM). I have confirmed that the physical switch has been replaced, but the symptoms persist, suggesting a deeper mechanical or electrical fault.

Related fault codes
P1899
Comments (4)
Anonymous 2018-03-19 12:03

Did you check for continuity in the P/N switch signal circuits? Possible Causes: - The P/N switch signal circuit is open between the switch and PCM. - The P/N switch signal circuit is shorted to sensor or chassis ground. - The P/N switch ground circuit is open (at the switch mounting point). - The P/N switch is stuck in park/neutral position or drive position. - The P/N switch is damaged or has failed. - The PCM may have failed.

Anonymous 2018-03-19 19:33

No, I haven't checked the circuits. How can I test for continuity or detect faults in these wiring paths?

Anonymous 2018-03-19 20:07

Hello everyone. It's possible that the gear lever is misaligned at either the lever end or gearbox end. Since gears follow a sequence of P → R → N → D, if the selector is displaced by two positions, it would result in neutral being detected as 'P' and reverse appearing as drive. This displacement could cause incorrect signals to the PCM. The most effective fix is to disconnect the gear linkage cable, manually locate the park position within the gearbox, then place the gear lever into park and reattach the linkage. This realigns the mechanical connection properly. Note that while the electric neutral safety switch acts as an inhibitor to prevent starting in gears other than park or neutral, it does not control gear engagement — the mechanical alignment is key.

Anonymous 2018-03-19 20:34

That makes perfect sense! I'll try repositioning the gear lever and realigning the linkage as suggested. Thanks for the clear explanation!