Radio Controls Malfunction (with Color Display)
Radio Controls Malfunction (with Color Display)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The radio controls are supplied battery voltage and ground. The radio controls the power state of the controls via a wake up circuit. Communications between the radio controls and the radio are through the CGI serial data circuits.
Reference Information
Schematic Reference
Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
Radio/Audio System Description and Operation Radio/Audio System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
1. Verify no DTCs are set as current.
• If any DTCs are set as current, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition ON, radio ON, verify the radio/HVAC controls backlighting illuminates and that all controls perform the correct function.
• If some, but not all, controls operate normally, replace the radio/HVAC control.
• If all controls are inoperative, refer to Circuit/System Testing.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the A22 radio controls.
2. Test for less than 10 ohms between the ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Test for less than 20 ohms between the data shield circuit terminal 6 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the A11 radio.
4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
5. Ignition ON, test for 2.4-2.75 V between the data circuit terminal 4 and ground.
• If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A11 radio.
• If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
6. Test for 2.4-2.75 V between the data circuit terminal 5 and ground.
• If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A11 radio.
• If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
7. Test for less than 1 V between the wake signal terminal 7 and ground.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
8. Test for less than 1 V between the reset signal terminal 8 and ground.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.
9. Ignition OFF, reconnect the harness connector at the A22 radio controls.
10. Disconnect the X1 harness connector at the A11 radio.
11. Install a DMM between wake signal terminal 13 and ground.
12. Ignition ON, verify the DMM reading is 4.5-5.5 V DC.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A22 radio controls.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A22 radio controls.
13. Press the power button on the radio controls. Verify the DMM reading is momentarily less than 1 V and returns to 4.5-5.5 V DC each time the power button is pressed.
• If not the specified value, replace the A22 radio controls.
14. Test for 4.5-5.5 V between the reset signal terminal 27 and ground.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A22 radio controls.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A22 radio controls.
15. If all circuits test normal, replace the A22 radio controls and reconnect all harness connectors.
16. Ignition ON, radio ON, verify the radio/HVAC controls backlighting illuminates and that all controls perform the correct function.
• If the radio/HVAC controls are still inoperative, replace the A11 radio.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests.
Control Module References Programming and Relearning for radio or radio control assembly replacement, setup, and programming.