DTC B2980 or DTC indicator F and Windshield Defrost: A short in the A/C Pressure Sensor Circuit

WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.

Clear the DTC with the HDS
Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode
Do the self-diagnostic with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS ) or the climate control unit (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS )
Check for DTCs
Is DTC B2980 or F and WINDSHIELD DEFROST indicated?

YES -Go to step 5

NO -Intermittent failure Check for loose wires or poor connections on the A/C pressure sensor circuit
Check for DTCs
Are these DTCs also present, B1234 or K and AUTO, and/or B1237 or N and AUTO, and/or B2968 or B and WINDSHIELD DEFROST?

YES -Go to step 16

NO -Go to step 6
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
Disconnect the A/C pressure sensor 3P connector
Disconnect climate control unit connector C (20P)
Check for continuity between body ground and climate control unit connector C (20P) terminal No 11

Fig 1: Checking Continuity Between Body Ground And Climate Control Unit Connector C (20P) Terminal 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short to body ground in the wire between the climate control unit and the A/C pressure sensor

NO -Go to step 10
Check for continuity between climate control unit connector C (20P) terminals No 2 and No 11

Fig 2: Checking Continuity Between Climate Control Unit Connector C (20P) Terminals 2 And 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short in the wires

NO -Go to step 11
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between body ground and climate control unit connector C (20P) terminal No 11

Fig 3: Measuring Voltage Between Body Ground And Climate Control Unit Connector C (20P) Terminal 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there any voltage?

YES -Repair short to power in the wire between the climate control unit and the A/C pressure sensor This short may also damage the climate control unit Repair the short to power before replacing the climate control unit

NO -Go to step 12
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
Reconnect climate control unit connector C (20P)
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode
Measure the voltage between climate control unit connector C (20P) terminals No 1 and No 2, and between climate control unit connector C (20P) terminals No 1 and No 11

Fig 4: Measuring Voltage Between Climate Control Unit Connector C (20P) Terminals 1 And 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?

YES -Replace the A/C pressure sensor

NO -Check for loose wires or poor connections at climate control unit connector C (20P) and at the A/C pressure sensor 3P connector If the connections are good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and disconnect climate control unit connector C (20P)
Disconnect these items
- Driver's air mix control motor
- Passenger's air mix control motor
- Humidity/in-car temperature sensor
- A/C pressure sensor
Check for continuity between climate control unit connector C (20P) terminal No 2 and body ground

Fig 5: Checking Continuity Between Climate Control Unit Connector C (20P) Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short to body ground in the wire

NO -Go to step 19
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between the same terminal and body ground

Fig 6: Checking Voltage Between Climate Control Unit Connector C (20P) Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there any voltage?

YES -Repair short to power in the wire This short may have also damaged the climate control unit Repair the short to power before replacing the climate control unit

NO -Go to step 20
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
Reconnect climate control unit connector C (20P)
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode, and measure the voltage between climate control unit connector C (20P) terminal No 2 and body ground

Fig 7: Measuring Voltage Between Climate Control Unit Connector C (20P) Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?

YES -Go to step 23

NO -Check for a loose wire or poor connection at climate control unit connector C (20P) If the connection is good, substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see Climate Control Unit Removal/Installation )
While measuring the voltage as described in step 22, reconnect these items individually and note the voltage reading each time
- Driver's air mix control motor
- Passenger's air mix control motor
- Humidity/in-car temperature sensor
- A/C pressure sensor
Fig 8: Measuring Voltage Between Climate Control Unit Connector C (20P) Terminal 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the voltage remain at about 5 V?

YES -Substitute a known-good climate control unit, and recheck If the symptom/indication goes away, replace the original climate control unit (see Climate Control Unit Removal/Installation )

NO -Replace the component that caused the voltage drop