The main compatibility issue I foresee are the O2 sensors. All 2003 to 2007 Gen III trucks use “Isolate ground” O2 sensors (ground controlled by the PCM). The 1999 to 2002 4.8L and 5.3L trucks predominantly use “Case ground” O2 sensors (ground directly). With the 6.0L, from 1999 to 2002, the O2 sensors could be:
•Isolate ground (front) and Case ground (rear)
•Isolate ground (all - front and rear)
Regards,
Taz
By way of example ….
If your current wiring harness and PCM tune are designed to work with Case Grounded O2 sensors:
•the PCM requires a “high” and “low” signal from each O2 sensor
•B1S1 “High” is typically connector C1 pin 69 (pin B on the O2 sensor)
•B1S1 “Low” is typically connector C1 pin 29 (pin A on the O2 sensor)
•B2S1 “High” is typically connector C1 pin 66 (pin B on the O2 sensor)
•B2S1 “Low” is typically connector C1 pin 26 (pin A on the O2 sensor)
•
the O2 sensors self ground (pin C on the O2 sensor)
If your current wiring harness and PCM tune are designed to work with Isolated Grounded O2 sensors:
•the PCM requires a “high” signal from each O2 sensor
•the PCM requires “low” signal from each O2 sensor - BUT the wires from pin A of all four O2 sensors merge in a mutual splice pack, THEN connect to their respective PCM pin locations
•the PCM also requires a “low reference” signal - mutual to all four O2 sensors
•B1S1 “High” is typically connector C1 pin 69 (pin B on the O2 sensor)
•B1S1 “Low” is typically connector C1 pin 29 (pin A on the O2 sensor)
•B2S1 “High” is typically connector C1 pin 66 (pin B on the O2 sensor)
•B2S1 “Low” is typically connector C1 pin 26 (pin A on the O2 sensor)
•
the mutual low reference signal is typically connector C1 pin 63 (pin A from all O2 sensors)
All front O2 sensors on the 1999 - 2003 6.0 L are “Isolate Ground” variants. The rear O2 sensors on the 6.0 L could be either Case Ground or Isolate Ground. As long as the O2 sensors you wish to use as a substitute are Isolate Ground - they should work just fine.
GM used a mix of O2 connectors in those years - flat, square, triangular, and of various colors.
Bookmarks