• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Park Lamp Relay Control | 2 | 1 | B2585 00 | -- |
Park Lamp Switch On Signal | B257A 00 | B257A 00 | B257A 00 | -- |
Left Park Lamp Control | 3 | 3 | 3 | -- |
Right Park Lamp Control | 4 | 4 | 4 | -- |
Left Park Lamp Ground | -- | 3 | 3 | -- |
Right Park Lamp Ground | -- | 4 | 4 | -- |
Headlamp Switch Ground | -- | 5 | -- | -- |
1. All Park Lamps Inoperative 2. All Park Lamps Always On 3. Left Park Lamps Malfunction 4. Right Park Lamps Malfunction 5. Headlamps and Park Lamps Inoperative |
The park, tail, marker, and license lamps are turned ON when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The underhood fuse block supplies B+ to both the park lamp relay switch contacts and the park lamp coil circuit. The body control module (BCM) provides a ground or control circuit to the park lamp circuit. When the park lamps are requested ON, the BCM energizes the park lamp relay. Current flow is from the park lamp relay to the individual park lamp circuit fuses and to their respective park, tail, marker, and license lamps.
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If all park lamps are inoperative, refer to Park Lamps Inoperative - All |
⇒ | If one or more, but not all, park lamps are inoperative, refer to Park Lamps Inoperative - One or More |
⇒ | If the park lamps are always illuminated, refer to Park Lamps Always ON |
⇒ | If the parameter does not cycle between the specified values, refer to Park Lamp Switch Malfunction. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
• | RPO W49/WDA - terminal B |
• | RPO Z88 - terminal D |
⇒ | If greater than the specified range, test the ground circuit for a open/high resistance. |
• | RPO W49/WDA - terminal C |
• | RPO Z88 - terminal A |
⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. |
• | LF/RF Marker Lamp (WDA) - Terminal 1 |
• | LF/RF Marker Lamp (W49/Z88) - Terminal B |
• | LR/RR Marker Lamp (WDA/W49) - Terminal B |
• | Left/Right Tail Lamp Assembly (Z88) - Terminal D |
• | Left/Right Tail Lamp (W49/WDA) - Terminal B |
• | LR/RR Park Lamp (Z88) - Terminal 2 |
• | LR/RR Park Lamp (W49) - Terminal A |
• | Left/Right License Lamp - Terminal B |
⇒ | If greater than the specified range, test the ground circuit for a open/high resistance. |
• | LF/RF Marker Lamp (WDA) - Terminal 2 |
• | LF/RF Marker Lamp (W49/Z88) - Terminal A |
• | LR/RR Marker Lamp (WDA/W49) - Terminal A |
• | Left/Right Tail Lamp Assembly (Z88) - Terminal A |
• | Left/Right Tail Lamp (W49/WDA) - Terminal A |
• | LR/RR Park Lamp (Z88) - Terminal 1 |
• | LR/RR Park Lamp (W49) - Terminal B |
• | Left/Right License Lamp - Terminal A |
⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. |
⇒ | If the park lamps are illuminated, test the control circuit for a short to voltage. |
⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |