A/C Clutch Relay (ACCR) Malfunction

DTC P1460 DETECTION CONDITION AND POSSIBLE CAUSE

DTC P1460	A/C CLUTCH RELAY (ACCR) MALFUNCTION
DETECTION CONDITION	P1460 indicates excessive current draw is detected on the ACCR circuit when the PCM grounds the circuit or voltage is not detected on the ACCR circuit when the circuit is not grounded by the PCM.
POSSIBLE CAUSE	A/C on during Self Test. Open or shorted ACCR circuit. Damaged ACCR. Damaged PCM. Open VPWR circuit to ACCR.
HINT	ACCR Description The Wide Open Throttle Air Conditioning Cut-off (WAC) output is used by the PCM to disengage the A/C clutch when A/C compressor operation is desirable. Under normal conditions (with the A/C off), the PCM will ground the WAC output, which opens the normally closed A/C clutch relay. When the A/C demand switch is turned on, and the A/C cycling switch and A/C high pressure switch contacts are closed, voltage is supplied to the A/C clutch relay contacts and to the ACCS circuit. The voltage on the ACCS circuit indicates to the PCM that A/C is requested. The PCM will then verify that A/C clutch operation is desirable and adjust the idle speed as necessary and unground the WAC output. This closes the normally closed WOT A/C clutch relay and allows voltage to the A/C clutch.
Courtesy of MAZDA MOTORS CORP.

DTC P1460 INSPECTION

STEP	INSPECTION		ACTION
1	Was PCM Quick Test performed?	Yes	Go to next step.
1	Was PCM Quick Test performed?	No	Perform PCM Quick Test.
2	KOEO/KOER DTC P1460: VERIFY ACCS PID IS OFF NOTE: If only Continuous Memory DTC P1460 is present, go to step 8. NOTE: For A/C always ON, refer to A/C ALWAYS ON AND A/C COMPRESSOR RUNS CONTINUOUSLY . NOTE: Verify A/C and defrost were off during KOEO/KOER Self Tests. If the vehicle is not equipped with A/C, the ACCR circuit is not used and DTC 1460 can be ignored. Start the engine. A/C and defroster off. Access A/C Control Signal (ACCS) PID. Is ACCS PID off?	Yes	Key OFF. Go to next step.
2		No	Key OFF. Go to step 2 of See A/C CONTROL SIGNAL (ACCS) MALFUNCTION to check A/C circuits for short to power.
3	CHECK FOR VPWR TO A/C CLUTCH RELAY Disconnect A/C clutch relay. Key ON, Engine OFF (KOEO). Measure voltage of VPWR circuit between A/C clutch relay vehicle harness connector and chassis ground. Is voltage greater than 10.5 V?	Yes	Go to next step.
3		No	Repair open in VPWR circuit. Reconnect A/C clutch relay. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
4	CHECK A/C CLUTCH RELAY Key OFF. Refer to pin numbers molded on A/C clutch relay. Measure resistance between pin 1 and all other pins of the A/C clutch relay. One measurement should be between 40 and 120 ohms and the other measurements should be greater than 10K ohms. Are all resistance checks OK?	Yes	Go to next step.
4		No	Replace A/C clutch relay. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
5	CHECK A/C CLUTCH CIRCUIT FOR SHORT TO POWER IN HARNESS Key OFF. Disconnect PCM. Install Breakout Box, leave PCM disconnected. Key ON, Engine OFF (KOEO). Measure voltage between PCM test pin 69 (ACCR) and chassis ground. Key OFF. Was voltage less than 1.0 V?	Yes	Go to next step.
5		No	Repair short to power. Remove Breakout Box. Reconnect all components. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
6	CHECK ACCR CIRCUIT FOR SHORT TO GROUND IN HARNESS Disconnect NGS Tester from DLC. Measure resistance of ACCR circuit between A/C clutch relay vehicle harness connector and ground. Is resistance greater than 10K ohms?	Yes	Go to next step.
6		No	Repair short circuit. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
7	CHECK ACCR CIRCUIT CONTINUITY Measure resistance of ACCR circuit between PCM test pin 69 and A/C clutch relay harness connector. Is resistance less than 5.0 ohms?	Yes	Replace PCM. See COMPUTERIZED ENGINE CONTROLS . Reconnect all components. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
7		No	Repair open circuit Reconnect all components. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
8	CONTINUOUS MEMORY DTC 1460: CHECK ACCR CIRCUIT FOR INTERMITTENT SHORT TO GROUND NOTE: If the vehicle is not equipped with A/C, the ACCR circuit is not used and P1460 can be ignored. Key ON, Engine OFF (KOEO). Check ACCR circuit for short to ground while performing the following: Shake, wiggle and bend the ACCR circuit between the PCM and the A/C clutch relay. Lightly tap on the A/C clutch relay (to simulate road shock). NOTE: The A/C clutch will click on when a fault is indicated. Is resistance greater than 10K ohms?	Yes	Key OFF. Repair short circuit. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
8		No	Go to next step.
9	CHECK ACCR CIRCUIT FOR INTERMITTENT OPEN OR SHORT TO POWER Access Output Test Mode with NGS Tester. Check ACCR circuit for open or short to power while performing the following: Shake, wiggle and bend the ACCR circuit between the PCM and the A/C clutch relay. Shake, wiggle and bend the VPWR circuit to the A/C clutch relay. Lightly tap on the A/C clutch relay (to simulate road shock). NOTE: The A/C clutch will click on when a fault is indicated. Is resistance greater than 10K ohms?	Yes	Key OFF. Repair open or short circuit. Start the engine. Turn A/C on, wait 15 seconds. A/C OFF. Key OFF. Go to step 10.
9		No	Unable to duplicate or identify fault at this time. See TEST 4: INTERMITTENT .
10	VERIFY TROUBLESHOOTING OF DTCs COMPLETED Make sure to reconnect all disconnected connectors. Clear DTCs from PCM memory using NGS tester generic OBD-II function. Perform PCM Quick Test. Is same DTC present?	Yes	Replace PCM. See COMPUTERIZED ENGINE CONTROLS . Repeat PCM QUICK TEST .
10		No	If any other DTC is present, go to applicable DTC inspection. If no DTC is present, troubleshooting complete.