JWT TCU Info

[rsiwicki]

With many thanks to AGM for doing the research and answering several of our questions regarding the TCU....Here are the correspondence emails between JWT & AGM that he has asked me to post

1. Does the JWT Trimode TCU still allow you to do a self diagnostic test onthe Transmission?

Yes, should be ok.

2. Will the JWT Trimode TCU cause any fault codes to be displayed on the display panel on the dash?

No.

3. No Core is required on the 3 mode JWT TCU as it is built from scratch?

Yes, that is correct.

4. Does the switch/wiring come with the JWT TCU?

Yes.

5. Where is the switch placed in the car?

Where ever you want it. The cable is 6 feet long.

6. What exactly do the '3 modes' actually do?

A) 2nd gear start with standard original programB) 1st gear with high shift (shifts at a little higher RPM than before)C) Snow mode (holds you in the gear you are in when activated but you can still manually go down or up gears.)

7. I have a ford 9" Rear end with 4:11:1 gears. Will this negatively affect the shift points to the transmission?

No. The TCU uses the driveshaft speed to determine shift point.

8. ***Do you sell a different 3 mode JWT TCU for a 90-93 Q45 and a 90-94 Q45?

No.

9. I am contemplating putting a 1990 RE4R03A (51X65) into my 1994 Q45, to get even lower 1st and 2nd gears. I will need to know if the JWT trimode is equally as suitable in both situations before I start swapping Transmissions. I'm not sure how the 51X65 will react to a stock OEM 1994 ECU, due to the TCU using the speed sensor to deal with shifts vs load.....the 8% and 5% lower gears might present some weird WOT shifts.....the transmission might not shift before hitting the rev limiter in 1st and 2nd gear.

Year 90-93 94-96Transmission RE4R03A RE4R03AModel 51X65 51X791st gear 2.784 2.5692nd gear 1.544 1.4793rd gear 1.000 1.0004th gear 0.694 0.694Reverse 2.275 2.275

Shift points are done by output shaft speed (the driveshaft.) If you are using the original unmodified ECU for the engine, then there might be a problem with the trans controller letting the rpm get higher and holding with the rev limiter. If you are using our upgraded JWT ECU for the engine, then there will be no problem.

Here is a response that I got back from JWT about Q45 upgrades....

Thanks for your interest in JWT products. Here is a list of what we have for the 1990-95 Infiniti Q45.

ECU upgrade $695.00 on an exchange basis. Call for current turnaround time. Available for 1990-95 models at this time only. 96+ models ECUs are in development. We do offer a core exchange option. The refundable additional core deposit is an additional $500.00. Contact us for more details.

PQ450-1453X Pop-Charger air intake system $159.00 (1990-96)PQ457-1X0DX Pop-Charger air intake system $159.00 (97+)

ECU and Pop-Charger net about a 28 HP gain together.

The JWT NOS system adds an additional 100 HP when used with the parts below.NQ450-NX152 NOS Control module 90-93 $450.00 (this unit gets installed inside a JWT upgraded ECU)NQ454-NX152 NOS Control module 94-95 $450.00 (this unit gets installed inside a JWT upgraded ECU)N4N20-HWARE NOS Hardware kit $637.00 (NOS bottle, bracket, braided hose, spray nozzle, solenoid, relay, wiring and plumbing, instructions.)

Transmission Control Unit upgrade $495.00 on an exchange basis (1990-95 models only,) (core deposit if needed is an additional $400.00.)This upgrade makes the transmission start in first and can also be set-up with slightly higher shift points with less throttle depression needed to cause a downshift (like a sports mode setting.)

3 mode Transmission Control Unit upgrade $650.00 on an exchange basis (1990-95 models only,) (core deposit if needed is an additional $400.00.) This upgrade is similar to the basic transmission control unit upgrade above except that is has a switchable 3 mode program that allows switching between either the std. original program, the 1st gear start with the program above and a 3rd option that will hold the trans in the gear that it is in.

Note: prices subject to change after 2/04 without notice, call to confirm all pricing.

[maxnix]

Interesting, but all the references to original programming starting in second gear and first gear start optional gives me pause about their knowledge of the differences in OEM TCU, let alone that JWT doesn't account for the differences in the 1st and 2nd gear ratios between the two main types of G50 transmissions.

[HeavyDuty]

It's just on that mode that you can do that. High shift will upshift 1-2 when it feels like it. I haven't tried keeping it in 2nd for an unwanted 2-3 shift, gives me something to do on the way to work.