Working on swapping a 5.7 hemi/545RFE from a 2006 Jeep Grand Cherokee (JGC) (+ NV/NP242 from unknown donor) into 1984 Grand Wagoneer. I wasn't able to complete all the desired testing before I got rid of the donor chassis. I'm currently working through trying to determine what wiring and modules I can drop from the donor. I have and intend to retain in the swap: PCM, IPM, FCM, PDM. I'd like to retain cruise control (and many other body functions) which is the biggest reason I'm troubleshooting this. The current issue that is tripping me up:
The JGC cluster displays all expected gauges and idiot lights but not vehicle speed. Cheap OBD scan tools/scan gauge II also report 0 MPH. VSS/trans output sensor is outputting a sinewave when running/in gear, to PCM C4-32 & C4-34 but I don't have a way to know what voltage/period it should have. ABS module is plugged in, but since I'm not swapping the JGC axles (and driveshafts are also not connected) it is receiving no WSS signals. I tried faking a signal, but again don't have a known good waveform to work from. Any suggestions on where I should be looking?
The Jeep is an interesting donor. It is half truck, half car in design. Meaning, it shares LX car hemi parts and truck hemi parts. In a car, the ABS module is the way the speed is monitored and transferred to the Other modules as in the CANBUS network. It is probably looking for the ABS sensors to calculate speed. What you can try is to change the tune settings. In HP tuners, try switching the can communication for speed “off.” Let us know how that works