LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2005 >> Century Custom >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Computer/Integrating Systems >> Diagnostic Information and Procedures >> DTC B1477 >> Test Description

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 2:  Listen for an audible click when the RAP relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
  2. 3:  This step tests for voltage at the coil side of the RAP relay. The INADV POWER BUS fuse supplies power to the coil side of the RAP relay.
  3. 4:  This step verifies that the BCM is providing ground to the RAP relay.
  4. 5:  This step tests if ground is constantly being applied to the RAP relay.
DTC B1477

Step Action Yes No
Schematic Reference: Retained Accessory Power (RAP) Schematics 
Connector End View Reference: Computer/Integrating Systems Connector End Views 
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2 
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the RAP relay ON and OFF.
Does the retained accessory power (RAP) relay turn ON and OFF with each command?		 Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems Go to Step 3 
3 
  1. Turn OFF the ignition.
  2. Disconnect the RAP relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Using a test lamp that is connected to a good ground, probe the RAP relay coil supply voltage circuit at the RAP relay.
Does the test lamp illuminate?		 Go to Step 4  Go to Step 10 
4 
  1. Connect a test lamp between the RAP relay control circuit and the RAP relay coil supply voltage circuit at the RAP relay.
  2. With a scan tool, command the RAP relay ON and OFF.
Does the test lamp turn ON and OFF with each command?		 Go to Step 8  Go to Step 5 
5  Does the test lamp remain illuminated with each command? Go to Step 7  Go to Step 6 
6 Test the control circuit of the RAP relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 9 
7 Test the control circuit of the RAP relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 9 
8 Inspect for poor connections at the RAP relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 11 
9 Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 Go to Step 13  Go to Step 12 
10 Test the relay coil supply circuit of the RAP relay for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you complete the repair?		 Go to Step 13  -
11 Replace the RAP relay.
Did you complete the repair?		 Go to Step 13  -
12 Replace and reprogram the BCM. Refer to Control Module References  for replacement, setup and programming.
Did you complete the repair?		 Go to Step 13  -
13
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.
Does the DTC reset?		 Go to Step 2  System OK
scientia non olet · About LEMON Manuals