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Wiring Harness & PCM Programming Services
for the
GM Generation III+ Engines

GM Wiring Harness for Jeeps

One of the most significant things an installer can do to speed the conversion process along and keep the headaches at bay is to have their factory GM harness simplified and modified. Novak has gotten this wiring process and PCM programming down to a science.

Wiring Harness
Typically, the conversion installer will get the factory engine harness from the donor vehicle. This will include the every wire and connector between the PCM and the engine's sensors (Oxygen, Throttle Position, Crank Position, etc.) and the active systems (coil triggers, injectors, IAC, etc.).

Novak can simplify this harness, removing unnecessary circuits, consolodating circuits, rerouting and labelling for a simpler 5-6 wire hookup into any Jeep.

Vehicle Speed Sensor
This sensor will allow you to run a conventional cable drive speedometer and send critical speed data to your GM PCM for proper powertrain operation.

Harness Mods at a Glance :

Identifying Your GM PCM
GM Generation 3+ PCM's come in three major styles as follows:

The early Generation III PCM, 1997 to 1998 The late Generation III PCM, 1999 to mid-2007 The Generation IV PCM w/transmission controller, 2005-present


Wiring harness modification service, GM Gen III+
Part #: HM-G3
Weight: 14.00
Price: $529.00
Axle Ratio:
Tire Diameter:
A/C:yes +$30 No
Rear O2 Sens.:Eliminate Retain
EGR:Eliminate Retain
EVAP:Eliminate Retain
electric fan:yes +$30 No
Model- Year- VIN::
PCM Programming:
NSS:yes +$30 No
GM Gen. III + engine control wiring harness modifications. Includes fuse & relay centers, harness simplification, rerouting, testing, labelling, minor repair where necessary and re-looming


Computer Programming at a Glance:

Programming, Powertrain Control Module, GM
Part #: PCM-P
Weight: 4.00
Price: $194.00
Axle Ratio:
Tire Diameter:
Rear O2 Sens.:Eliminate Retain
Model- Year- VIN::
Gen III or Gen IV:Gen IV +$68 Gen III +$0
Programming, Powertrain Control Module, GM. Includes VATS removal, tire size & axle ratio, emissions modifications as requested, and optimization


GM PCM Mounting Assembly
Need a cool way to attach your PCM to your Jeep? Our PCM mounting bracket assembly is the best thing to come along in this area for some time.

Shipping Instructions
Please see our Contact page, where you'll find our physical address to which you can send your harness and/or computer. When shipping, we recommend you insure your harness for the typical value of a new replacement harness, which is commonly ~$900 and computer for ~$250. We will associate your Shopping Cart order with your harness/computer when they arrive.

Please do not send anything other than the harness with your shipment. We do not need the throttle pedal, fuse box, battery terminals, or any other sub harnesses, just the engine wiring harness. If you are not sure if it is part of the engine or GM chassis harness, send it and we'll discard as necessary.

Make sure to let us know your phone number and e-mail address when ordering. The Novak shopping cart will ask for these details. We are likely to call or e-mail you with any questions and confirmations.

Currently, typical turnaround time is under 12 days, plus shipping time as you've chosen (Ground, Third Day, Second Day, etc.)

Please note that if your PCM or its wires are damaged or in need of repair before it can be used, you may incur an up-charge for the additional labor.

Wiring Harnesses in Conversions

- Also see: Vehicle Speed Sensors