The following actions cue the body control module (BCM) type 4 to activate the headlamps and the horn:
• | The keyless entry systems remote control door lock receiver (RCDLR) sends a message to activate the alarm mode. |
• | The BCM detects a theft attempt when the content theft deterrent is in either the armed or warning mode. |
• | The theft deterrent system is in the trunk open mode. |
The BCM interfaces with the headlamps through the theft deterrent relay. The theft deterrent relay allows the BCM to turn the headlamps ON providing a visual alert. The BCM energizes the theft deterrent relay, turning the headlamps ON by grounding CKT 352 during the following modes:
• | The armed mode |
When the content theft deterrent is in the armed mode, the BCM turns the headlamps ON once for 950-1000 ms. The BCM turns on the headlamps only if the remote activation verification is in either mode 2, 3 or 4. Refer to Body Control Module Diagnostic Information . The horn also sounds during this mode. The BCM will sound the horn first then the headlamps will flash. |
• | The warning mode |
The warning mode attempts to warn away potential intruders prior to setting off the alarm mode. The headlamps will cycle ON and OFF 5 times at a rate of 0.9-1.1 hz with a 15-25% active state duty cycle. The horn will sound 5 times during this mode although the BCM alternates between the horn and the headlamps. |
• | The alarm mode |
When the content theft deterrent is in the alarm mode, the BCM will turn the headlamps ON and OFF for 2 minutes or until the alarm is disarmed at a rate of 0.9-1.1 hz with a 15-25% active state duty cycle. The horn will sound during this mode although the BCM alternates between the horn and the headlamps. |
• | The trunk open mode |
This mode warns the vehicle operator that the content theft deterrent is waiting for the trunk to be closed before going into an armed mode. After the BCM sounds the horn for 23-27 ms, the BCM turns the headlamps ON for 950-1000 ms. This activation only takes place if the remote activation verification is in mode 2, 3 or 4. |
The BCM detects a short to B+ or ground in CKT 352.
• | The BCM sets the diagnostic trouble code (DTC) 6. |
• | The BCM does not turn on the headlamps during the armed, warning, alarm or trunk open modes. |
• | If CKT 352 is shorted to ground, the headlamps will stay ON at all times. |
• | A short to B+ or ground in CKT 352 is no longer present between the BCM and the theft deterrent relay. |
• | After the repairs are completed, refer to Body Control Module Diagnostic Information |
• | Inspect for a short to B+ or ground in CKT 352. |
• | A faulty theft deterrent relay. |
• | Move the wiring and the connectors while you complete the following tests. This will cause the malfunction to appear. |
Complete the following steps in order to change the remote activation verification mode:
• | The BCM will sound a chime the number of times equivalent to the BCM type installed on the vehicle. |
• | The BCM has entered the feature customization mode. |
• | In order to change the remote activation verification mode, press the lock button on the keyless entry transmitter. |
• | The BCM will sound a chime the number of times equivalent to the remote activation verification mode. |
The following are the remote activation verification modes:
• | Mode 1 |
The remote activation verification is disabled. |
The horn and headlamps are not activated. |
• | Mode 2 |
The headlamps will flash when the doors are locked or unlocked using the keyless entry transmitter. |
• | Mode 3 |
The headlamps will flash when the doors are unlocked using the keyless entry transmitter. |
The headlamps will flash and the horn will sound when the doors are locked using the keyless entry transmitter. |
• | Mode 4 |
The headlamps will flash when the doors are locked or unlocked using the keyless entry transmitter. |
The headlamps will flash and the horn will sound when the doors are locked using the keyless entry transmitter a second time within 5 seconds of locking the doors with the keyless entry transmitter. |
The BCM will sound a chime the number of times equivalent to the BCM type installed on the vehicle.
The BCM will sound any DTCs that are stored.
The BCM enters the Input/Output test. There are 7 steps in the Input/Output test:
• | Test 1 |
Test 1 de-energizes CKT 1393 (protected courtesy lamp output). |
• | Test 2 |
Test 2 energizes CKT 1393. |
• | Test 3 |
Test 3 grounds CKT 690 (courtesy lamps control). |
• | Test 4 |
Test 4 energizes the theft deterrent relay for 1 second by grounding CKT 352 and turns on the headlamps (BCM type 4 only). |
• | Test 5 |
Test 5 energizes the horn relay for 25 ms by grounding CKT 28 and sounds the horn (BCM type 4 only). |
• | Test 6 |
Test 6 turns on the theft deterrent indicator lamp by grounding CKT 749 (BCM type 4 only). |
• | Test 7 |
Test 7 turns off the theft deterrent indicator lamp by opening CKT 749 (BCM type 4 only). |
The BCM completes the steps of the Input/Output test in numerical order.
In order to move to the next test, cycle the IP dimmer switch from DOME to OFF then back to DOME. The BCM will sound a chime a number of times equivalent to the Input/Output test number above. The Input/Output test sequence repeats until the ignition switch is turned to the OFF position.
The number(s) below refer to the step number(s) on the diagnostic table.
Always perform the BCM diagnostic system check before attempting to diagnose this DTC.
This step checks ability of the BCM to turn on the headlamps.
This step checks for a short to B+ in CKT 352.
This step checks for a short to ground in CKT 352.
This step for a faulty theft deterrent relay.
This step determines whether the condition is intermittent and not related to a faulty BCM.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
Was the BCM Diagnostic System check performed? | -- | Go to Step 2 | ||
Perform the BCM Input/Output test. Refer to Body Control Module Diagnostic Information for procedure. Do headlamps turn on for one second when the BCM Input/Output performs test 4? | -- | Go to Step 6 | Go to Step 3 | |
Is the resistance less than the specified value? | 2 V | Go to Step 4 | Go to Step 7 | |
Use a DMM to measure the resistance between the BCM harness connector C2 terminal D11 and ground. Is the resistance equal to the specified value? | OL (infinite) | Go to Step 5 | Go to Step 8 | |
Use DMM to measure the resistance between the theft deterrent relay terminals A1 and C2 (relay side). Is the resistance within the specified range? | 65-110 ohms | Go to Step 6 | Go to Step 9 | |
Does DTC 6 reset? | -- | Go to Step 10 | Go to Step 11 | |
7 | Repair short to voltage in CKT 352. Is the repair complete? | -- | Go to Step 12 | -- |
8 | Repair short to ground in CKT 352. Is the repair complete? | -- | Go to Step 12 | -- |
9 | Replace the theft deterrent relay. Is the repair complete? | -- | Go to Step 12 | -- |
10 |
Is the action complete? | -- | Go to Step 12 | -- |
11 | Malfunction not present at this time. Refer to Diagnostic Aids for additional information. Is the action complete? | -- | Go to Step 12 | -- |
12 |
Are there any BCM DTCs present? | -- | System OK |