Jeep Cherokee Forum (https://www.cherokeeforum.com/)

- - Limp Mode? (https://www.cherokeeforum.com/f2/limp-mode-276017/)

New to me 1998 Cherokee XJ, 4.0L, 2WD with 38k miles. It’s acting like it’s in limp mode — starts off in what feels like 3rd gear and is very sluggish. If I manually select 1–2, it shifts normally and accelerates strong.

I’m getting a P1698 (no CCD message from TCM). I’ve already unplugged and inspected the TCM connector, and no visible corrosion or loose pins.

Previous owner replaced the crank position sensor, alternator, distributor cap/rotor, plugs, and wires.

From what I understand this points to a TCM communication issue — possibly wiring, power/ground, or the TCM itself. Before I start chasing the harness or swapping modules, has anyone dealt with this issue and found a common failure point (fuse, ground, CCD bus issue, etc.)?

Here’s the exact, correct test procedure for the AW4 solenoids on your 1998 Jeep Cherokee (XJ). The AW4 uses three solenoids—Shift Solenoid 1, Shift Solenoid 2, and the Torque Converter Clutch (TCC) solenoid. All three can be tested with a multimeter at the transmission’s 8‑pin connector or directly at the solenoids.

Below is the full diagnostic procedure used by Jeep/Aisin‑Warner service manuals and XJ tech forums.

🔧 AW4 Solenoid Test Procedure (1998 Jeep Cherokee)

1️⃣ Identify the Solenoids

Solenoid Function Normal Resistance Solenoid 1 (S1) Controls 1–2 shift logic 11–15 Ω Solenoid 2 (S2) Controls 2–3 shift logic 11–15 Ω Solenoid 3 (TCC) Torque converter lockup 11–15 ΩThese values are consistent across AW4 years.

2️⃣ Access the Transmission Harness Connector

The AW4 external harness connector is on the passenger side of the transmission, 8‑pin rectangular plug.

Pinout (1998 XJ)

Pin 1 – Solenoid 1
Pin 2 – Solenoid 2
Pin 3 – Solenoid 3 (TCC)
Remaining pins: power feed, NSS, speed sensor, ground.

3️⃣ Resistance Test (Key OFF)

This is the fastest way to confirm solenoid health.

Steps

Disconnect the 8‑pin transmission connector.
Set multimeter to ohms.
Measure between:
- Pin 1 → Ground (S1)
- Pin 2 → Ground (S2)
- Pin 3 → Ground (TCC)
Expected reading: 11–15 Ω.

Interpretation

Open circuit (∞ Ω) → failed solenoid or broken wire.
Very low resistance (<5 Ω) → shorted solenoid.
Correct resistance but still no shifting → wiring or TCM issue.

4️⃣ Power/Activation Test (Optional)

This confirms the solenoid physically clicks.

Steps

Apply 12V+ to the solenoid pin.
Ground the solenoid body.
You should hear/feel a click.

⚠️ Do NOT apply power for more than 1–2 seconds at a time.

5️⃣ TCM Output Test (Checks wiring + TCM)

If solenoids test good but shifting is wrong:

Steps

Back‑probe the TCM connector under the dash (right of steering column).
With key ON, monitor voltage on:
- TCM Pin 7 – S1
- TCM Pin 8 – S2
- TCM Pin 9 – TCC
Drive or simulate throttle input.
You should see the TCM switch 0V → 12V depending on gear logic.

If the TCM never commands a solenoid, the issue is upstream (NSS, TPS, VSS, grounds).

6️⃣ Hydraulic Confirmation (If Electronics Pass)

If all electrical tests pass but shifting is still wrong, the AW4 valve body may have:

Sticking valves
Contaminated ATF
Worn accumulators

🧰 Quick Reference: AW4 Gear Logic Table

Gear S1 S2 1st ON ON 2nd OFF ON 3rd ON OFF 4th OFF OFFThis helps diagnose “stuck in 3rd” or “no OD” conditions.

Want the valve body connector diagram, TCM pinout, or step‑by‑step solenoid replacement?

I can give you the exact wiring colors and the AW4 valve body layout if you want to go deeper.

Just to confirm—the connector for the ohms test is the black plug next to the transmission dipstick, correct? If that’s the one, it measured 12 ohms on all 3 pins, so I’ll proceed to the TCM output test.

I’m struggling to find an accurate diagram of the TCM plug to identify the pins. None of the diagrams I’ve come across match my connector, so I’m wondering if I’m looking at the wrong one. Here’s a photo of what I have.
https://cimg3.ibsrv.net/gimg/www.che...2d588648ed.jpg

I’m stuck at this point. I’ve tested all the pins and can’t find anything wrong—grounds are solid and power is present where it should be. I even picked up a second TCM from the pick-and-pull, but it didn’t change the symptoms.

I’m not sure if it’s related to the problem or not, but the 20A ABS fuse keeps blowing and shows constant 12 volts, even with the key off.

I am about ready to light it on fire!

common is the solenoids. not hard to remove and bench test
common in vehicles that has not had proper transmission fluid changes is valve body gummed up.
these transmissions are very tough and hardly have problems for their age
1) make sure you have adjusted your kick down cable
2) I would pull the solenoids and replace them if necessary.
3) fluid change with the correct dex/merc fluid. If the fluid in the trans smells burnt or looks almost black...this probably won't help, but it is cheaper than a rebuild or other transmission to try.

https://cimg8.ibsrv.net/gimg/www.che...54901dcce.jpeg
oh look, I can copy/paste upload too

Then copy/paste upload something useful...
He has a code that has nothing to do with solenoids. You just copied and pasted his post to AI then copied and pasted that here. He could've done that himself.

I double-checked the power supply, (switched and not switched), and ground connections, and followed the procedure for checking the CCD Bus +/- (thanks to Wrongholefool). Everything tested fine, so the only conclusion I can come to is that both TCMs I have might be faulty. Does anyone have a TCM they’d be willing to sell? : )

The issue has been resolved. It turns out I had two faulty TCMs. After replacing one with a unit from eBay, everything is now working properly. Thanks to everyone that assisted!