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Yellow05C6
April 10th, 2025, 01:30 PM
I'm helping install a Turbo 5.3L (LS1B) into a 2002 Trailblazer that originated life with a 4.2L (P10 ECM). Does anyone know if the two ECMs share compatible serial data streams? (i.e., will the LS1B and TAC module 'play nice' with the 2002 Trailblazer's A/C, Cruise Control, Dash instruments, etc?)

ScarabEpic22
April 10th, 2025, 06:34 PM
Flash the LS1B with an 02/03 5.3L V8 file from an extended TB and just remove the P10 altogether. It's a factory combo so should work well.

RhiannaWyman
April 23rd, 2025, 07:35 PM
I'm helping install a Turbo 5.3L (LS1B) into a 2002 Trailblazer that originated life with a 4.2L (P10 ECM). Does anyone know if the two ECMs share compatible serial data streams? (i.e., will the LS1B and TAC module 'play nice' with the 2002 Trailblazer's A/C, Cruise Control, Dash instruments, Geometry Dash (https://geometrydash-lite.io), etc?)
Hello Yellow05C6!
Have you loaded Flash the LS1B with an 02/03 5.3L? I tried it and found it quite stable.

Prock1950
June 6th, 2025, 04:01 PM
I'm helping install a Turbo 5.3L (LS1B) into a 2002 Trailblazer that originated life with a 4.2L (P10 ECM). Does anyone know if the two ECMs share compatible serial data streams? (i.e., will the LS1B and TAC module 'play nice' with the 2002 Trailblazer's A/C, Cruise Control, Dash instruments, etc?)
The P10 and LS1B ECMs use different serial data protocols, so they're not directly compatible when it comes to modules like the BCM, IPC, or TAC. In a 2002 Trailblazer, the P10 communicates via Class 2 (J1850), while the LS1B from a 5.3L setup also uses Class 2, but implementation can vary depending on the donor vehicle. You may run into issues with A/C controls, cruise, and dash functionality unless you either reprogram modules to match or use a standalone setup for the engine and retain factory systems with a data bridge or custom tuning