Code 41: Abnormal Signal Output To Engine Control Module

NOTE: Code 41 is output when serial communication circuit between TCL module and Engine Control Module (ECM) is interrupted due to open or short circuit.

Ensure ignition is off. Disconnect TCL module harness connector and ECM harness connector. See Figure and Figure . Connect jumper wires between TCL module terminals No. 7 and ground, and No. 17 and ground. See Figure .
Using ohmmeter, check continuity between selected ECM harness connector terminals and ground. See Figure and Figure . See CODE 41 CONTINUITY CHECK table. If continuity exists, go to next step. If continuity does not exist, inspect and repair circuit as needed. See appropriate wiring diagram in WIRING DIAGRAMS.
Disconnect jumper wires. Check continuity between TCL harness connector terminals No. 7 and 17, and ground. If continuity does not exist, go to next step. If continuity exists, inspect and repair circuit(s) for short to ground.
Check continuity between TCL harness connector terminals No. 7 and 17. If continuity exists, inspect and repair circuit(s) for short as needed. If continuity does not exist, substitute ECM with known good unit. Clear trouble codes. See CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Test drive vehicle. Retrieve codes.
If code 41 is output, replace TCL module. If code 41 is not output, replace ECM.

CODE 41 CONTINUITY CHECK

TCL Terminal No. ⁽¹⁾

⁽²⁾ ECM Terminal No.

California Vehicles

Federal Vehicles

⁽¹⁾	See Figure .

⁽²⁾	See Figure and Figure .