Nissan RE5R05A No Reverse and Delayed Reverse: P1767, P1769, Pilot Valve Wear and the Real Fix

Nissan RE5R05A No Reverse and Delayed Reverse: P1767, P1769, Pilot Valve Wear and the Real Fix

Nissan RE5R05A No Reverse and Delayed Reverse: P1767, P1769, Pilot Valve Wear and the Real Fix

You back out of the driveway and nothing happens for two seconds. Then the truck slams into Reverse. A month later it will not go into Reverse at all, but it still drives forward through all five gears. If that is your Nissan Titan, Frontier, Xterra, Pathfinder, Armada or Infiniti, you are looking at a RE5R05A, and the problem is almost never that the transmission is shot. It is usually a worn valve body bore starving the Reverse-side solenoids of feed pressure. That distinction separates a valve body repair from a full teardown, and the two look identical from the driver seat.

Which unit do you have?

The RE5R05A is a Jatco five-speed rear-wheel-drive automatic. Per Sonnax, it has been on the street since 2002, when it first appeared in the Infiniti Q45 with the 4.5L engine, and Nissan and Infiniti have used it in many models since (Sonnax, RE5R05A Facts and Observations, Jeff Parlee, December 31, 2009).

Before you order anything, identify the valve body, because they are not interchangeable. Sonnax documents the design levels this way:

  • 1st design - two neutral-to-Reverse accumulators on the lower body behind the manual valve, and an empty valve bore under the low coast solenoid.
  • 2nd design - the same two neutral-to-Reverse accumulators, but a Reverse brake pressure control valve now occupies the bore that was empty on the 1st design.
  • 3rd design - one large neutral-to-Reverse accumulator instead of two.

Sonnax states plainly that these designs should not be interchanged, and carries the split into reman part numbers: NIS501 and NIS502 are 1st design, NIS504 and NIS505 are 2nd design, NIS507 is 3rd design, with the Infiniti-only versions separated by low coast solenoid resistance (Sonnax, Jatco/Nissan RE5R05A Valve Body Identification). That same chart also lists a 4th design, so verify against the diagram rather than assuming there are only three.

The solenoid trap: Infiniti used a low-resistance low coast solenoid measuring 10-15 ohms until August 2005, then switched to the same high-resistance 20-40 ohm solenoid Nissan has always used. Bosch, Nachi and Mitsubishi have all built low coast solenoids for this unit, and Sonnax says they can be freely interchanged as long as the resistance matches, identifying them by the plastic at the O-ring area: brown on the early 10-15 ohm Infiniti-only unit, black on the Bosch and Nachi types, white on the Mitsubishi type.

Diagnosis: read the codes before you drop the pan

The RE5R05A uses discrete solenoids for each clutch, and the TCM sets a specific code for each one. From the Sonnax RE5R05A trouble code chart (Sonnax, RE5R05A Trouble Code Chart), the codes that matter for a Reverse complaint are:

  • P1767 - High & Low/Reverse Clutch Solenoid, Circuit. Set when the TCM detects an improper voltage drop in the solenoid circuit. Listed causes: wiring, bad ground, the High & Low/Reverse solenoid, TCM.
  • P1769 - High & Low/Reverse Clutch Solenoid, Function. Set when the TCM detects an improper gear ratio. Listed causes: the solenoid, valve body, High & Low/Reverse clutch slip, pressure switch 6, PNP switch, output speed sensor, TCM.
  • P0745 - EPC solenoid circuit, an improper voltage drop in the line pressure control circuit.
  • P1757 / P1759 and P1762 / P1764 - front brake and direct clutch solenoid, circuit and function.

Read that split carefully, because it drives the whole repair. A circuit code is electrical: wiring, ground, or the solenoid itself. A function code means the TCM commanded the clutch and did not get the gear ratio it expected, and Sonnax lists the valve body and actual clutch slip as causes right alongside the solenoid. P1769 with no P1767 is a hydraulic or mechanical story, not a wiring story.

A practical order of operations:

  1. Check fluid level and condition first. Brown, varnished or milky fluid changes the answer.
  2. Look for coolant in the fluid. Sonnax reports that about half the cores they receive have water intrusion from failed coolers in the radiator, and recommends replacing the cooler even if it has not failed yet. If your fluid is pink or milky, stop and read our RE5R05A coolant-in-the-fluid writeup before you spend money on clutches.
  3. Pull codes and separate circuit from function.
  4. Ohm the solenoid that matches the circuit code against the correct spec for your unit and build date.
  5. If it is a function code and the solenoid checks out, the valve body is the suspect.

The cause: pilot valve bore wear

Here is the part most people miss. The RE5R05A solenoids do not see line pressure directly. They are fed through pilot valves, and Sonnax spells out exactly which solenoids each one feeds:

In Jatco/Nissan RE5R05A units, pilot valve "A" feeds the line pressure modulating solenoid, and the TCC solenoid. Pilot valve "B" feeds the following solenoids: direct and input clutch, front brake band, low coast brake and high and low/Reverse.
Sonnax, "A" or "B" Pilot Valve Kit 63741-13K

So the High & Low/Reverse clutch solenoid, the one behind P1767 and P1769, lives downstream of pilot valve "B". Sonnax describes the wear pattern in both directions: wear at the inboard end causes excessive feed pressure, which floods the solenoids, reduces reaction time, and produces harsh shifting and high line pressure. Wear at the outboard spool lets fluid leak into the sump port, reducing solenoid modulator pressure, and Sonnax notes that this loss has the most effect on engagements and on boost oil for line pressure rise.

Engagements. That is your delayed and no Reverse: the solenoid can be fine and the clutch can be fine, but the oil that should be commanding it is leaking into the sump through a worn aluminum bore.

The second common cause sits upstream of that: pressure regulator and boost sleeve wear. Sonnax states that these units may exhibit insufficient line rise, resulting in delayed engagement, slipping in Reverse, poor shift quality, erratic line pressure and burnt clutches, and attributes it to wear in the OE pressure regulator valve bore and/or boost sleeve, which allows the pressure to escape (Sonnax, Oversized Pressure Regulator & Boost Valve Kit 63741-01K). On the Sonnax RE5R05A unit page, both 63741-13K and 63741-01K are listed against the No Reverse and Delayed Reverse symptoms (Sonnax RE5R05A unit page).

The fix: which part, and why

Match the repair to what the diagnosis actually found.

Circuit code (P1767, P1757, P1762) with an out-of-spec solenoid: replace the solenoid. Sonnax offers 63425 as an OE-quality direct replacement covering the direct clutch, input clutch, and high and low Reverse clutch solenoid positions in this unit (Sonnax 63425). Because this transmission uses one common solenoid across three positions, a solenoid kit is usually the better buy than a single piece.

RE5R05A shift solenoid kit for Nissan Titan, Frontier, Xterra and Pathfinder
RE5R05A Shift Solenoid Kit - covers the direct clutch, input clutch and high/low Reverse solenoid positions in one part. Browse all transmission shift solenoids.

Function code (P1769) with a good solenoid: the valve body is the target. Recondition the pilot valve "B" bore and install the Sonnax "A" or "B" pilot valve kit 63741-13K. Sonnax notes the kit uses a hardcoat anodized aluminum valve, adds annular grooves for better centering in the bore, provides over 50 percent more support than the OE casting, and includes new calibrated springs so the bore can be set up as either the "A" or the "B" pilot valve. If line pressure is low across the board, add 63741-01K for the pressure regulator and boost sleeve.

Actual Reverse clutch damage: if pressure switch and gear ratio data show real slip and the fluid is burnt, the High & Low/Reverse clutch pack is cooked and the unit comes out. At that point the valve body work still has to happen, or the new clutches will burn for the same reason the old ones did.

Replace while you are in there

Whether you are doing a valve body repair or a full rebuild, these go in at the same time:

Cost and effort

A valve body R and R on this unit is a pan-down job with the transmission still in the vehicle. Figure roughly 3 to 5 hours of labor for pan, filter, valve body out, solenoid replacement and reassembly, at a moderate difficulty level. It is bolts, a wiring connector and careful cleanliness, not special tooling.

Reconditioning the pilot valve or pressure regulator bore is a different tier. Sonnax lists dedicated tooling for those repairs, F-63741-TL13 for the pilot valve kit and F-63741-TL for the pressure regulator kit, so unless you own that setup, the bore work goes to a valve body specialist or you buy a remanufactured valve body in the correct design. A full rebuild is a transmission-out job and jumps to the 10 to 15 hour range plus a rebuild kit and a torque converter. That gap is exactly why the diagnosis matters.

FAQ

Can I just swap in a used valve body from a junkyard RE5R05A?
Only if the design level and the low coast solenoid resistance both match. Sonnax states the designs should not be interchanged, and the reman part numbering splits Infiniti 10-15 ohm units from Nissan 20-40 ohm units. A mismatched swap is how a running truck becomes a no-move truck.

My truck has delayed Reverse but no codes at all. Is it still the valve body?
It can be. Pilot valve and pressure regulator wear cause pressure loss that shows up as delayed engagement long before the gear ratio drifts far enough for the TCM to set a function code. Sonnax lists both delayed Reverse and no Reverse against those valve body repairs regardless of code status. Check line pressure and fluid condition first.

Does the RE5R05A share parts with anything else?
Yes. Sonnax notes the pilot valve kit also fits Hyundai/Kia A5SR1 and A5SR2 and the Subaru 5EAT, and that solenoids 63425 and 63421 also fit Hyundai/Kia A5SR1 and A5SR2. Useful for cross-referencing, but confirm fitment by unit and year rather than by family. For a model-by-model breakdown, see our Nissan Titan and Frontier transmission guide.

Sources