For a complete wiring diagram Refer to Section 8W.When Monitored:Continuously.Set Condition:When the Totally Integrated Power Module (TIPM) detects a HIGH condition.Possible CausesCHECK (Z910) GROUND CIRCUIT(Z910) GROUND CIRCUIT OPENCHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT(L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT OPEN(L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT SHORTED TO VOLTAGETOTALLY INTEGRATED POWER MODULE1. TEST FOR INTERMITTENT CONDITIONTurn the ignition on.With the scan tool, clear all DTC's.Turn the Left Turn Signal on.With the scan tool, read DTC's.Does the scan tool display active: B1644-REAR LEFT TURN LAMP CONTROL CIRCUIT HIGH?YesGo To 2NoThe condition that caused this symptom is currently not present. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) 2. CHECK (Z910) GROUND CIRCUITSTurn the ignition off.Disconnect the Left Rear Turn Signal Lamp assembly harness connector.With a 12–volt test light connected to 12–volts, probe each (Z910) Ground circuit.Does the test light illuminate brightly on each ground circuit?YesGo To 4NoGo To 33. (Z910) GROUND CIRCUIT OPENMeasure the resistance of the appropriate (Z910) Ground circuit(s) at the Left Rear Turn Signal Lamp assembly harness connector.Is the resistance below 10.0 ohms?YesReplace the Inoperative bulb in accordance with the Service Information.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) NoRepair the appropriate (Z910) Ground circuit(s) for an open.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) 4. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUITTurn the ignition on.With the Left Turn Signal still on and a 12–volt test light connected to ground, check the (L63) Left Rear Turn Signal Control circuit.Does the test light blink brightly from on to off with the turn signal indicator?YesReplace the Inoperative bulb in accordance with the Service Information.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) NoGo To 55. (L63) LEFT TURN SIGNAL CONTROL CIRCUIT OPENTurn the ignition off.Disconnect the TIPM C4 harness connector.Measure the resistance of the (L63) Left Rear Turn Signal Control circuit between the Left Rear Tail Lamp assembly harness connector and the TIPM C4 harness connector.Is the resistance below 10.0 ohms?Yes Go To 6No Repair the (L63) Left Rear Turn Signal Control circuit for an open.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) 6. (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT SHORTED TO VOLTAGETurn the ignition on.Measure for voltage on the (L63) Left Rear Turn Signal Control circuit.Is there any voltage present?YesRepair short to voltage on the (L63) Left Rear Turn Signal Control circuit.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE) NoReplace the Totally Integrated Power Module (TIPM) in accordance with the Service Information.Perform the BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)