P0725

Engine speed input circuit malfunction

Detection Condition

• While vehicle speed is 25mph or higher, the engine speed signal from the crankshaft position sensor (CKP) indicates 470 rpm or below for 2 seconds or more

Diagnostic Support Notes

• This is a continuous monitor (CCM)
• The check engine indicator illuminates if the TCM detects the above malfunction condition in two consecutive drive cycles
• PENDING CODE data is available
• FREEZE FRAME DATA is available
• HOLD indicator flashes
• DTC is stored in TCM memory

Possible Causes

• Crankshaft position sensor malfunction
• Short to ground between TCM terminal 1G and ECU
• Open circuit between TCM terminal 1G and ECU
• Short to power between TCM terminal 1G and ECU
• Damaged connectors between TCM and ECU
• TCM malfunction
• ECU malfunction
• *Engine stall while traveling 25mph or higher

Diagnostic procedure

If this code appears with P0335, perform diagnostic on the crankshaft position sensor circuit, clear trouble codes and verify repair.  Otherwise, inspect the connectors and wiring between the engine control unit and transmission control module for damage, open circuits, and shorts.  Clear any stored codes and verify repair.  If P0725 persists, replace the transmission control module.  If P0725 still persists, replace the engine control unit. *See notes.

[P0725 - From 2002 Mazda Millenia factory service manual]

Notes: Engine stall that occurs while cruising, caused by timing belt breakage/slippage, ignition system failure, or even running out of fuel, may store a P0725 code after the stall event.  If the engine now turns over but will not start and the only code stored is P0725, see Symptom Troubleshooting #6 - Cranks normally but will not start.