Powertrain Control Module (Pcm) Malfunction

NOTE: The following test procedures are for DTCs P0603, P0605, P0606, P1633 and P1639.

Fig 1: Powertrain Control Module (PCM) Malfunction Detection Condition Possible Cause

Courtesy of MAZDA MOTORS CORP.

POWERTRAIN CONTROL MODULE (PCM) MALFUNCTION INSPECTION/ACTION CHART

STEP	INSPECTION		ACTION
1	Was PCM Quick Test performed?	Yes	For DTC P0605 or P1639, go to next step. For all others, go to step 3.
1	Was PCM Quick Test performed?	No	Perform PCM Quick Test. See PCM QUICK TEST .
2	PROGRAM PCM PARAMETERS Connect WDS or equivalent tester with flash cable. Key ON, Engine OFF (KOEO). Select Diagnostic Data Link. Select PCM. Select Module Configuration and follow directions to access. Scroll to tire size and press Trigger. Turn dial to select 720 for 235/70R16 tires or 749 for 215/70R16 tires then press Trigger. Scroll to axle ratio and press Trigger. Turn dial to select 3.78 and press Trigger. Press Start to program PCM parameters. Press Cancel to return to the first screen. Was programming successful?	Yes	Clear DTCs and perform a brief drive cycle (of at least 1/4 mile). Start and stop the vehicle two times during the drive, cycling the key off and on. Go to step 6.
2		No	See DIAGNOSTIC INDEX .
3	CHECK BATTERY TERMINALS NOTE: If KAPWR is interrupted to the PCM (that is, when a Breakout Box is installed or the battery is disconnected), DTCs P0603/P1605 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.
3		No	Repair battery terminals as necessary. Go to step 6.
4	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 6.
4		No	Engine compartment wire routing is OK. Go to next step.
5	CHECK KEEP ALIVE POWER (KAPWR) TO PCM Disconnect PCM. Install Breakout Box, leave PCM disconnected. Measure voltage between test pin C45 (KAPWR) and test pin C49 (PWR GND). While observing multimeter, grasp the engine harness and wiggle, shake or bend a small section 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.
5		No	No open in KAPWR harness circuit detected. Go to next step.
6	VERIFY TROUBLESHOOTING OF DTCs COMPLETED Make sure to reconnect all disconnected connectors. Clear DTCs from PCM memory using WDS or equivalent tester generic OBD II function. Perform PCM Quick Test. See PCM QUICK TEST . Is same DTC present?	Yes	Replace PCM. See POWERTRAIN CONTROL MODULE (PCM) . Repeat PCM Quick Test. See PCM QUICK TEST .
6		No	If any other DTC is present, go to applicable DTC inspection. If no DTC is present, troubleshooting complete.