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DTC B103A: Refrigerant PRS.SNS.circuit high
DTC B103B: Refrigerant PRS.SNS.circuit low
 
 
 
 
DTC SET CONDITION
These codes will be set when the refrigerant pressure sensor circuit is short to power supply (DTC B103A) or open or short to ground (DTC B103B).
noteWhen you have evacuated the system before filling with refrigerant, these codes will be set. On completion, erase these codes.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the A/C pressure sensor
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
  • Malfunction of the heater controller assembly (A/C-ECU)
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-IIISE), check the data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the electric motor switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect Scan Tool (M.U.T.-IIISE) ".
(2) Check that the following data list display contents are normal (Refer to ).
Item No.61: Pressure sensor
Is the check result normal?
Go to Step 4.
Go to Step 2.
 
STEP 2. Check of open and short circuit in SENB, AC/P, SENG - line between A/C pressure sensor and auto heater controller assembly (A/C-ECU) connector.
Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.
 
STEP 3. Check the A/C pressure sensor.
Refer to .
Is the check result normal?
Go to Step 4.
Replace the A/C pressure sensor (Refer to ).
 
STEP 4. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck the DTC.
(1) Erase the DTC.
(2) Electric motor switch: OFF to ON
(3) Check the DTC.
Is the DTC set?
Replace the heater controller assembly (A/C-ECU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).