LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 1999 >> B2500 TL, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Trouble Shooting & Fault Diagnosis >> A/C Control Signal (ACCS) Malfunction

A/C Control Signal (ACCS) Malfunction

DTC P1464 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P1464 A/C CONTROL SIGNAL (ACCS) MALFUNCTION
DETECTION CONDITION 
  • Self Test detected that the ACCS input to the PCM was high.
POSSIBLE CAUSE 
  • A/C was on during Self Test.
  • Short to power on ACCS SIG circuit.
  • Damaged A/C Demand switch.
  • Damaged WOT A/C cutoff relay.
  • Damaged A/C clutch relay.
  • Damaged PCM.
DTC P1464 INSPECTION

STEP INSPECTION ACTION
1 DTC P1464: CHECK ACCS PID
NOTE: Verify that A/C and defrost were OFF during Self Test. If A/C or defrost were on, turn off and rerun Self Test.
  • Key On Engine Off (KOEO).
  • NGS Tester connected.
  • A/C and defrost off.
  • Access ACCS PID.
  • Is ACCS PID on? 
 Yes Go to step 2.
No The ACCS PID indicates that the ACCS input to the PCM is low.
Verify test results.
With A/C and defrost OFF, rerun Self Test where P1464 was received.
See ON-BOARD DIAGNOSTIC TESTS 
2 ACCS PID ON: DISCONNECT A/C CYCLING SWITCH AND CHECK IF ACCS PID TURNS OFF
  • Key OFF.
  • Disconnect A/C Cycling Switch.
  • Key On Engine Off (KOEO).
  • Access ACCS PID.
  • Is ACCS PID off? 
 Yes Key OFF.
Verify operation of A/C Demand Switch.
  • TROUBLE SHOOTING in A/C-HEATER SYSTEM article in HVAC . If OK, repair short to power in A/C Demand circuit (PU) to A/C Cycling Switch.

GO to step 6.
No Key OFF.
Go to step 3.
3 CHECK POWER TO A/C CLUTCH CIRCUIT FOR SHORT TO POWER
  • Key OFF.
  • Disconnect WOT A/C cutoff relay.
  • Key ON.
  • Measure voltage between A/C clutch power circuit (GY/W) in harness connector and chassis ground.
  • Key OFF.
  • Was voltage less than 1.0 volt? 
 Yes Go to step 4.
No Repair circuit short to power.
Go to step 6.
4 CHECK ACCS CIRCUIT FOR SHORT TO POWER
  • Disconnect PCM.
  • Inspect for damaged or pushed out pins, corrosion and loose wires.
  • Repair as necessary.
  • Install Breakout Box, leave PCM disconnected.
  • Key ON.
  • Measure voltage between test pin 41 (ACCS) and test pins 51 and 103 (PWR GND).
  • Was voltage less than 1.0 volt? 
 Yes Go to step 5.
No Repair ACCS circuit to power.
Go to step 6.
5 CHECK ACCS CIRCUIT VOLTAGE TO PCM WITH WOT A/C CUTOFF RELAY CONNECTED
  • Reconnect WOT A/C cutoff relay.
  • Breakout Box installed, PCM disconnected.
  • Key ON.
  • Again measure voltage between test pin 41 (ACCS) and test pins 51 and 103 (PWR GND).
  • Key OFF.
  • Was voltage less than 1.0 volt? 
 Yes Replace PCM. See POWERTRAIN CONTROL MODULE .
GO to step 6.
No Replace WOT A/C cutoff relay.
Go to step 6.
6
scientia non olet · About LEMON Manuals