Pinpoint Test BA : U0253
- Normal Operation and Fault Conditions
REFER to: Electric Powertrain Control - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition SOBDMC U0253:87 Lost Communication With Accessory Protocol Interface Module: Missing Message This DTC sets when messages are missing from the APIM. Possible Sources
- Communications network concern
- APIM
- BA1 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Using a diagnostic scan tool, perform a network test.
Does the APIM pass the network test?
Yes GO to BA2 No DIAGNOSE the network concern. REFER to: Communications Network . - BA2 RETRIEVE THE APIM (SYNC MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, perform the APIM self-test.
Are any APIM DTCs recorded?
Yes REFER to: Information and Entertainment System - Vehicles With: SYNC 3 . No GO to BA3 - BA3 CHECK THE INVERTER SYSTEM CONTROLLER (ISC) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using the scan tool, clear the Inverter System Controller (ISC) DTCs.
- Wait 10 seconds.
- Using a diagnostic scan tool, retrieve the Inverter System Controller (ISC) DTCs.
Is DTC U0253:87 still present?
Yes GO to BA4 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - BA4 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0253:87 SET IN OTHER MODULES
- Using the scan tool, clear the Inverter System Controller (ISC) DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, retrieve the Inverter System Controller (ISC) DTCs.
Is DTC U0253:87 set in other modules?
Yes GO to BA5 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - BA5 CHECK FOR CORRECT APIM (SYNC MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all APIM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the APIM connectors. Make sure they seat and latch correctly.
- Ignition ON.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new APIM. REFER to: SYNC Module [APIM] . No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.