2011 Volvo C70FACTORY OEM SERVICE PROCEDURE

Start (-2005)

Fig 1: Identifying Starter Motor Relay, TCM, ECM, Control Solenoid & CEM
GLL117533Courtesy of VOLVO CARS CORPORATION

The starter motor (6/25) is powered via the starter motor relay (2/35). The relay is controlled by the engine control module (ECM) (4/46). The start process is as follows:

  1. The ignition key is turned to start position (position III)
  2. A high signal from the ignition switch (3/1) is transmitted to the engine control module (ECM) and starter relay via the central electronic module (CEM) and integrated relay/fusebox in the engine compartment. The engine control module (ECM) interprets this high signal as a request to activate the starter motor.
  3. The engine control module (ECM) activates the starter motor solenoid by grounding the relay for the starter motor relay. The relay is powered by the ignition switch
  4. The relay closes the circuit between the starter motor solenoid and the fuse in the integrated relay/fusebox in the engine compartment, activating the starter motor
  5. The engine control module (ECM) activates the starter motor until the ignition key is released from the start position (position III).

The starter motor will not be activated if:

  • the immobilizer function does not permit starting. The engine control module (ECM) receives a signal regarding whether the immobilizer is active or inactive from the central electronic module (CEM) via the control area network (CAN)
  • the gear selector is not in position "P" or "N" (automatic transmissions). The engine control module (ECM) receives a signal indicating the position of the gear selector from the transmission control module (TCM) (4/28) via both the controller area network (CAN) and from a directly connected cable between the engine control module (ECM) and transmission control module (TCM).
  • the clutch pedal is released (manual transmissions, certain markets). The engine control module (ECM) receives a signal indicating the position of the clutch pedal from the central electronic module (CEM) via the controller area network (CAN).
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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