Ford Fiesta Quiz
Body and Paint

Pinpoint Test - DTC: DD. Diagnosis and Testing

In this manual: Body and Paint
Service Information — 27Suspension — 48Transmission — 9Brake System — 52Steering — 21Engine — 140Manual Transmission, Clutch, Transfer Case and Power Transfer Unit — 48Exhaust System — 6Fuel System — 21Climate Control System — 58Instrumentation and Warning Systems — 26Battery and Charging System — 20Infotainment Systems — 41Lighting — 29Power Distribution — 11Electronic Function Group — 30Body and Paint — 275Frame and Mounting — 3
~3min read

U0253:00

Normal Operation and Fault Symptoms

The RCM uses the information contained in the messages from the APIM sent over the HS-CAN.


DTC Fault Trigger Conditions


Trouble Code Description Fault Trigger Conditions
U0253:00 Lost Communication with Auxiliary Protocol Interface Module: No Sub Type Information This DTC sets when the RCM does not receive an expected message from the APIM.

Possible Causes

  • Network Traffic
  • APIM
  • RCM

PINPOINT TEST A: U0253:00
NOTE: Most concerns are related to connector and/or wiring issues. Perform a thorough inspection and check before proceeding to the Pinpoint Test.
NOTE: Only disconnect or reconnect SRS components when instructed to do so in the Pinpoint Test step. Failure to follow this instruction may result in an incorrect SRS diagnosis.
NOTE: Always verify the correct SRS component is installed. Parts released for other vehicles may be incompatible even if they appear physically similar. Check the part number listed in the Ford parts catalog to confirm the correct component is installed. If an incorrect SRS component is installed, diagnostic trouble codes (DTCs) may be set.
NOTE: Before returning the vehicle to the customer, the SRS must be fully functional and operating correctly.
A1 CHECK THE COMMUNICATION NETWORK
  • The ignition is on.
  • Using the diagnostic scan tool, perform the network test.

Does the APIM pass the network test?
Yes GO to A2
No To diagnose a loss of communication with the APIM,
REFER TO: Communication Network (418-00 Module Communications Network).
A2 CHECK THE RCM (RESTRAINT CONTROL MODULE) CONTINUOUS MEMORY DIAGNOSTIC TROUBLE CODES (CMDTCS)
  • Using the diagnostic scanner, perform the RCM self-test.
  • Using the scan tool, clear the RCM diagnostic trouble codes (DTCs).
  • Wait 10 seconds.
  • Using the diagnostic scanner, perform the RCM self-test.

Is DTC U0253:00 retrieved again?
Yes GO to A3
No The system is currently operating correctly. The DTC may have been set due to high network traffic or an intermittent fault.
A3 RETRIEVE THE STORED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE RCM (RESTRAINT CONTROL MODULE) SELF-TEST
  • Check for stored diagnostic trouble codes (DTCs) using the RCM self-test.

Is DTC U3003:16 or U3003:17 recorded?
Yes
REFER TO: Pinpoint Test - DTC: FF (501-20B Supplemental Restraint System, Diagnosis and Testing).
No GO to A4
A4 RETRIEVE THE STORED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE APIM (SYNC MODULE) SELF-TEST
  • Using the diagnostic scan tool, perform the APIM self-test.
  • Check for stored diagnostic trouble codes (DTCs) from the APIM self-test.

Is DTC U3003:16 or U3003:17 recorded?
Yes CHECK the battery voltage diagnostic trouble codes (DTCs).
REFER TO: Audio/Video Entertainment System (415-00A Audio/Video Entertainment System - General Information - Vehicles With: AM/FM/CD/SYNC, Diagnosis and Testing).
REFER TO: Audio/Video Entertainment System (415-00 Audio/Video Entertainment System - General Information).
No GO to A5
A5 CHECK DTC (DIAGNOSTIC TROUBLE CODE) U0253:00 SET IN OTHER MODULES
  • Using the diagnostic scan tool, perform a self-test of all modules.

Is DTC U0253:00 set in the ACM?
Yes CHECK OASIS for any applicable technical service bulletins (TSBs). If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSBs apply to this concern, INSTALL a new APIM.
REFER TO: SYNC Module [APIM] (415-00A Audio/Video Entertainment System - General Information - Vehicles With: AM/FM/CD/SYNC, Removal and Installation).
REFER TO: SYNC Module [APIM] (415-00 Audio/Video Entertainment System - General Information).
No CHECK OASIS for any applicable technical service bulletins (TSBs). If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSBs apply to this concern, INSTALL a new RCM.
REFER TO: Restraints Control Module (RCM) (501-20B Supplemental Restraint System, Removal and Installation).

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