Converting 93 to 94 pcm, please help

[stngh8r]

Need your guidance. What am I missing?

The plan: Remove pcm, engine/trans harness, 4L60, MAF and injectors from my 94 donor car and put it on my 93.

My compatibility concerns:
-Cruise
-Diag. port
-BCM
-Gauge cluster and related warning lights

Thanks in advance
Eric

[casey20000007]

It's all still going to be obd1 u shouldn't have a problem


SMOKE TIRES NOT DRUGS

[bobdec]

Is the donor car going to be around. You covered cruise module, dash gauges (speedometer/tach) . Aldl is same connector just wiring to be verified, no BCM in the '94. You may want to swap the 4-wire O2's into the '93. AIR pump, Evap ,EGR, may require exhaust manifolds (for air), Intake (for EGR), TB for TPS, TB linkage for cruise and no more kickdown cable, Knock Sensor, intake snorkel, , oil pressure sensor moves up top. '93 has two relay fan setup (fan1 then fan 2) '94 has 3 relay (both low speed then both high speed) . I think '93 injectors were 22#, '94's are 24# may want to swap them or get it tuned. Trying to remember if ICM/Coil connectors are the same. As long as you have good wiring diagrams you s/b able to get past any problems.

[Injuneer]

Early production 94 had the same 2-relay fan control as the 93 (fan 1/fan 2). About mid-year they switched to the 3-relay (low/high) configuration.

The 93 IAC connector is different than 94.

There may be some mismatch between the engine harness connectors and the body connectors. Shoebox has a table of connector pinouts for each year:

http://shbox.com/1/harness_connector_faces.htm

There's something weird with the 93 speedo.... I believe the VSS feeds the speedo directly, while the 94 feeds the PCM and the PCM feeds the speedo. Check the wiring to the cruise as well.... the 93 VSS may split 3 ways - speedo/ECM/cruise. 94 goes only to the PCM, then from the PCM to the cruise module.

ALDL pinouts are the same.

The 94 wiring harness may be set up for the oil pressure sensor to be on the top/rear of the block (late 94) or on the driver's side of the block above the oil filter (93 and early 94).

Only the speedo and the tach interface with the PCM in a 94. Oil pressure, coolant temp, fuel level and voltage gauges are wired directly. Ditto 93 on the oil, coolant, fuel and voltage.

If you want, I can send you a link to a site where you can download both the 93 and 94 factory manuals.

93 tach wiring is different. Tach is fed from the coil, via a filter. 94 feed the tach from the PCM.

You indicate you are pulling the 4L60 from the 94 donor car - it should have a 4L60E.

[Still2slow]

The vehicle speed sensor pulse rate is different from 93 to 94+ as well. The 94+ has a faster pulse. If the VSS goes straight to the speedo on 93 (which I'm unsure of) you should be able to correct it with a Dakota digital speedo recalibration box spliced between the speedometer and VSS. If not I would think it'd be plug and play since your going 94 ECM and trans.

[casey20000007]

These guys know there shit lmao ok you can proceed now


SMOKE TIRES NOT DRUGS

[Still2slow]

ImageUploadedByTapatalk1369180314.984239.jpg

From my 1993 service manual, good to have in the ole workbench drawer

[b94z28]

I switched my 93 engine harness with a 94 harness and pcm..worked ..but aldl port wouldnt work..couldnt read the pcm..other than that every thing functioned..

[bobdec]

b94z28, In '93 ALDL connector pin 'M' Tan wire (serial data) went to ECM pin 'D03' , in the '94 ALDL connector pin 'M' tan wire (serial data) has to go to PCM pin 'D30' When you installed the '94 harness was there a tan wire on connector D pin 30 and was it routed to the ALDL connector Pin 'M' ?