2006 Mazda B3000 Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Powertrain Control Module (Pcm) Malfunction

DTC P0603, P1633, P1639 DETECTION CONDITION & POSSIBLE CAUSES

DTC P0603, P1633, P1639 POWERTRAIN CONTROL MODULE (PCM) MALFUNCTION
DETECTION CONDITION 
  • P0603 indicates that the PCM has experienced a power interrupt in the keep alive power (KAPWR) circuit or an internal memory test failure. However there are external items that can cause the DTC.
  • P1633 indicates that the KAPWR circuit has experienced a power interrupt.
  • P1639 indicates the vehicle ID (VID) block is not programmed or the information within is corrupt.
POSSIBLE CAUSE 
  • Battery terminal corrosion or loose connections (P0603)
  • Open KAPWR circuit (P1633)
  • KAPWR to PCM interrupt/open (P0603)
  • Damaged PCM (P0603, P1633)
  • Reprogramming (P0603)
  • Intermittent KAPWR circuit (P1633)
  • New powertrain control module (PCM) (P1639)
  • Incorrect PCM (P1639)
  • Incorrect VID configuration (P1639)
 HINT PCM Description 
  • Receives information from a variety of sensors and switch inputs. Based on the strategy and calibration stored within the memory chip, the PCM generates the appropriate output. The system is designated to minimize emissions and optimize fuel economy and driveability.
  • The software strategy:
  • Controls the basic operation of the engine and transmission.
  • Provides the OBD-II strategy.
  • Controls the malfunction indicator lamp (MIL).
  • Communicates to the WDS or equivalent tester via the data link connector (DLC).
  • Allows for flash electronically erasable programmable read only memory (FEEPROM).
  • Provides idle air and fuel trim.
  • Controls failure mode effects management (FMEM).
DTC P0603, P1633 DIAGNOSTIC PROCEDURE

DTC P0603, P1633 POWERTRAIN CONTROL MODULE (PCM) MALFUNCTION
STEP INSPECTION ACTION
1
  • Was the PCM quick test performed?
 Yes Go to next step.
No Perform PCM quick test. See PCM QUICK TEST  .
2 CHECK BATTERY TERMINALS
NOTE:
  • If KAPWR is interrupted to the PCM (that is, when a breakout box is installed or the battery is disconnected), DTC P0603 can be generated on the first power-up.
  • Inspect the battery cables for loose connections, corrosion.
  • Are the battery terminal connections in good condition? 
 Yes Go to next step.
No Repair battery terminals as necessary. Go to step 5.
3 INSPECT ENGINE COMPARTMENT FOR PROPER WIRE ROUTING
  • Inspect engine compartment wiring for proximity to ignition components or wires.
  • Is wiring too close to ignition components or wires? 
 Yes Reroute wires as necessary. Go to step 5.
No Engine compartment wire routing is OK. Go to next step.
4 CHECK KEEP ALIVE POWER (KAPWR) TO PCM
  • Disconnect PCM.
  • Install breakout box, leave PCM disconnected.
  • Measure voltage between test pin 55 (KAPWR) and test pin 103 (PWR GND).
  • While observing multimeter, wiggle, shake or bend a small section the engine harness while working from the PCM to the dash panel.
  • Does the voltage reading Indicate less than 10.5 V? 
 Yes Isolate and repair open in KAPWR circuit. Go to next step.
No No open in KAPWR harness circuit detected.
Go to next step.
5 VERIFY TROUBLESHOOTING OF DTCs COMPLETED
  • Connect all disconnected connectors.
  • Clear DTCs from PCM memory using WDS or equivalent tester.
  • Perform PCM quick test.
  • Is the same DTC present? 
 Yes Replace PCM.
See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION . Repeat PCM quick test.
No If any other DTC is present, Go to applicable DTC inspection. See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) . If no DTC is present, troubleshooting is complete.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
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