Where the flasher is located

Hi,

This vehicle does not use a traditional hazard/turn signal flasher. This function is controlled by the Body Control Module (BCM).

Are they doing anything? Do they turn on and not flash or does nothing work?

Here are the diagnostics for this. Take a look through these and let me know if it is something you feel comfortable doing.

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2008 Cadillac Truck Escalade AWD V8-6.2L
Turn Signal Lamps and/or Indicators Malfunction
Vehicle Lighting and Horns Testing and Inspection Symptom Related Diagnostic Procedures Turn Signal Lamps and/or Indicators Malfunction
TURN SIGNAL LAMPS AND/OR INDICATORS MALFUNCTION
Turn Signal Lamps and/or Indicators Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Vehicle > Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

When the turn signal switch is placed in either the left or right position, a ground signal is completed from the turn signal switch to the BCM. When the hazard flasher switch is activated, a ground signal is completed from the turn signal/hazard switch to the BCM. The BCM then sends an ON-OFF voltage signal through the fuses to the appropriate turn signal and side repeater (export only) lamps or to all of the turn signal fuses for hazard operation. The driver door switch and passenger door switch also receive voltage from the BCM turn signal supply voltage circuits for the mirror turn signals. The door switches have no function or control of the mirror turn signals other than a pass through connection for the circuits. The audio chime is also activated when the turn signals are ON. The instrument panel cluster (IPC) receives the signals to activate the turn signal indicators over the GMLAN serial data system.

Circuit/System Verification

1. Ignition ON, command the following ON and OFF with a scan tool. The respective turn signal lamp should turn on and off.

* LF Turn Signal
* LR Turn Signal
* RF Turn Signal
* RR Turn Signal

If the turn signal lamp is always on or does not turn on, refer to Turn Signal Lamp Circuit Malfunction.

2. Ignition ON, operate the left and right turn signals from the multi-function/turn signal switch and verify the left and right turn signal lamps and indicators operate normal.

If the left or right turn signals do not operate, refer to the Turn Signal Switch Circuit Test.

Circuit/System Testing

Turn Signal Lamp Circuit Malfunction
1. Ignition OFF, disconnect the X4 harness connector at the BCM.
2. Ignition ON, verify a test lamp illuminates between the following B+ terminals and ground.

* B+ terminal 1
* B+ terminal 2
* B+ terminal 3

If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the circuit fuse is open, test the B+ circuit and the affected turn signal control circuits for a short to ground.

3. Ignition OFF, connect the harness connector X4 harness connector at the BCM.
4. Disconnect the harness connector at the affected turn signal lamp.
5. Test for less than 1.0 ohms of resistance between the affected ground circuit terminal and ground.

* Front Chevy, GMC terminal C
* Front Cadillac terminal 3
* Repeater terminal 2
* Rear GMC terminal G
* Rear Chevy, Cadillac EXT terminal GRD
* Rear Cadillac SUV terminal D
* Outside mirror terminal 10

If greater than the specified range, test the ground circuit for an open/high resistance.

6. Connect a test lamp between the affected turn signal control circuit terminal and ground.

* Front Chevy, GMC terminal A
* Front Cadillac terminal 1
* Repeater terminal 1
* Rear GMC terminal A
* Rear Chevy, Cadillac EXT terminal MJR
* Rear Domestic Cadillac SUV terminal E
* Rear Export Cadillac SUV terminal B
* Outside mirror terminal 5

7. Ignition ON, command the affected turn signal on and off with a scan tool. The test lamp should turn on and off when changing between the commanded states.

If the test lamp is always on, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the BCM.

If the test lamp is always off, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, test or replace the affected turn signal bulb.

Turn Signal Switch Circuit Test
1. Ignition OFF, disconnect the harness connector 1 at the turn signal/multifunction switch.
2. Test for less than 1.0 ohm of resistance between the ground circuit terminal F and ground.

If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool left and right turn signal parameters are Inactive.

If not the specified value, test the affected signal circuit terminal for a short to ground. If the circuit tests normal, replace the BCM.

* Left terminal E
* Right terminal D

4. Install a 3A fused jumper wire between the affected signal circuit terminal and the ground circuit terminal F. Verify the scan tool left or right turn signal parameter is Active.

* Left terminal E
* Right terminal D

If not the specified value, test the affected signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the turn signal/multi-function switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: A L L Diagnostic Trouble Codes ( DTC ) > Verification Tests

* Park/Turn Signal Lamp Bulb Replacement (Tahoe, Avalanche) Park/Turn Signal Lamp Bulb Replacement (Cadillac) Park/Turn Signal Lamp Bulb Replacement (Yukon) Park/Turn Signal Lamp Bulb Replacement (Escalade)
* Tail Lamp Bulb Replacement (Cadillac) Tail Lamp Bulb Replacement (Yukon) Tail Lamp Bulb Replacement (Tahoe, Avalanche) Tail Lamp Bulb Replacement (GMC HP2)
* Turn Signal Multi-function Switch Replacement

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Let me know if this helps.

Take care,
Joe