For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Totally Integrated Power Module (TIPM) receives a bus message requesting low beam lamp illumination. When this bus message is received, the TIPM provides a voltage output through the low beam driver circuit. The low beam driver circuit connects to the Low Beam Lamp. A headlamp return signal circuit is used instead of a ground circuit.
When Monitored:
With the low beam headlamps active.
Set Condition:
When the Totally Integrated Power Module (TIPM) detects a high condition on the (L43) Left Low Beam Driver circuit.
Possible Causes
(L43) LEFT LOW BEAM DRIVER CIRCUIT OPEN
(L43) LEFT LOW BEAM DRIVER CIRCUIT SHORTED TO VOLTAGE
(L911) LEFT HEADLAMP RETURN SIGNAL CIRCUIT OPEN
LEFT LOW BEAM BULB
TOTALLY INTEGRATED POWER MODULE (TIPM)
1.
INTERMITTENT CONDITION
1.
Turn the ignition on.
2.
With the scan tool, clear all DTCs.
3.
Turn the Headlamps on.
4.
With the scan tool, read DTCs.
Does the scan tool display DTC: B162C-LEFT LOW BEAM CONTROL CIRCUIT HIGH?
Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
Connect a 12-volt test light between the (L43) Left Low Beam Driver circuit and (L911) Left Headlamp Return Signal circuit in the Left Headlamp Lamp harness connector.
4.
Turn the ignition on.
5.
Turn the Headlamps on.
Does the test light illuminate brightly?
Yes
Replace the Left Low Beam Bulb in accordance with the Service Information.
5.
CHECK THE (L911) LEFT HEADLAMP RETURN SIGNAL CIRCUIT FOR AN OPEN IN THE HARNESS
1.
Measure the resistance of the (L911) Left Headlamp Return Signal circuit between the Left Headlamp Lamp harness connector and the TIPM C3 harness connector.
Is the resistance below 5.0 Ohms?
Yes
Replace the Totally Integrated Power Module (TIPM) in accordance with the Service Information.
