Retained Accessory Power Malfunction
Diagnostic Instructions
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
RAP/ACCY Relay Switch B+
|
3
|
4
|
2
|
-
|
RAP/ACCY Relay Control
|
B1445 02
|
1
|
1
|
-
|
RAP/ACCY Relay Ignition
|
3
|
4
|
2
|
-
|
RAP/ACCY Relay Ground
|
-
|
1
|
-
|
-
|
1. All relay controlled retained power accessory functions
inoperative.
2. Relay retained power accessory remains on past the timer limit
after key out and will not turn off when a vehicle door is
opened.
3. Partial relay controlled retained power accessory functions
inoperative with open fuse.
4. Partial relay controlled retained power accessory functions
inoperative with fuse OK.
|
|
|
Circuit/System Description
The retained accessory power system allows specific vehicle
functions to operate after the ignition is turned OFF for a
predetermined time. Relay retained accessory power is controlled by
the body control module (BCM) using inputs from the door ajar
switches to determine control of the relay when the ignition is
turned OFF. Radio retained accessory power is controlled by a
serial data message from the BCM using inputs from the driver door
open switch. Refer to
Retained Accessory Power Description and Operation for more
detail on subsystems using retained accessory power.
Diagnostic Aids
The radio retained accessory power mode is a separate function
and will still operate properly. The radio retained accessory power
function is controlled by serial data and the specific module.
These functions are not affected by the BCM retained accessory
power relay circuits.
Reference Information
Schematic Reference
Connector End View Reference
Component Connector End Views
Description and Operation
Retained Accessory Power Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Note: Battery voltage must
remain above 9.6 V for retained accessory power to operate
properly.
Radio Retained Accessory Power
1. |
With all passenger doors
closed, observe the courtesy lamps while opening and closing the
driver door. The courtesy lamps should illuminate when the door is
opened and turn off approximately 30 seconds after closing the
door. |
2. |
If courtesy lamp operation is
correct, and the radio is the only retained accessory power
concern, replace the radio. |
Relay Retained Accessory Power
1. |
Ignition ON, observe the
appropriate scan tool parameters listed below while opening and
closing each vehicle door. The reading should change between Door
Closed/Door Ajar. |
|
• |
Driver Door Ajar Switch
|
|
• |
Left Rear Door Ajar
Switch |
|
• |
Passenger Door Ajar
Switch |
|
• |
Right Rear Door Ajar
Switch |
2. |
Command the scan tool
Accessory/Retained Accessory Power Relay Command OFF. Attempt to
operate any retained accessory power relay controlled component
within 5 seconds. The component should not operate. |
3. |
Command the scan tool
Accessory/Retained Accessory Power Relay Command ON. Attempt to
operate any retained accessory power relay controlled component
within 5 seconds. The component should operate. |
4. |
Ignition ON, all doors closed.
Observe the scan tool parameter Accessory/Retained Accessory Power
Relay Command. Ignition OFF, key removed, the reading should be ON
for approximately 10 minutes then change to OFF. |
⇒ |
If the parameter does not respond as specified,
replace the K9 BCM. |
Circuit/System Testing
1. |
Ignition OFF, disconnect the
KR70 RAP/ACCY relay. |
2. |
Test for less than 10 Ω
between the ground control circuit terminal 86 and ground.
|
⇒ |
If greater than the specified range, test the
ground circuit for an open/high resistance. |
3. |
Verify that a test lamp
illuminates between the B+ circuit terminal 30 and ground.
|
⇒ |
If the test does not illuminate, test the B+
circuit for short to ground or an open/high resistance. |
4. |
Connect a test lamp between
the control circuit terminal 85 and the ground circuit terminal
86. |
5. |
Command the RAP/ACCY relay ON
and OFF with a scan tool. The test lamp should turn ON and OFF when
changing between the command states. |
⇒ |
If the test lamp is always ON, test the control
circuit for a short to voltage. If the circuit tests normal,
replace the K9 BCM. |
⇒ |
If the test lamp is always OFF, test the control
circuit for a short to ground or an open/high resistance. If the
circuit tests normal, replace the BCM. |
6. |
Connect the RAP/ACCY relay.
Disconnect the harness connector at the center console accessory
power outlet. |
7. |
Connect a test lamp between
the ignition circuit terminal A and ground. |
8. |
Command the RAP/ACCY relay ON
and OFF with a scan tool. The test lamp should turn ON and OFF when
changing between the command states. |
⇒ |
If the test lamp is always ON, test the control
circuit for a short to voltage. If the circuit tests normal, test
or replace the KR70 RAP/ACCY relay. |
⇒ |
If the test lamp is always OFF, test the control
circuit for a short to ground or an open/high resistance. If the
circuit tests normal, test or replace the KR70 RAP/ACCY relay. |
Component Testing
1. |
Ignition OFF, disconnect the
KR70 RAP/ACCY relay. |
2. |
Test for 70-150 Ω
between terminals control circuit terminal 85 and ground terminal
86. |
⇒ |
If not within the specified range, replace the
KR70 RAP/ACCY relay. |
3. |
Test for infinite resistance
between the following terminals: |
⇒ |
If not the specified value, replace the KR70
RAP/ACCY relay. |
4. |
Install a 2 A fused jumper
wire between relay terminal 85 and 12 V. Install a jumper wire
between relay terminal 86 and ground. Test for less than 2 Ω
between terminals 30 and 87. |
⇒ |
If greater than the specified range, replace the
KR70 RAP/ACCY relay. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
|