Engine Control System - Removal & Installation, System Checking (Convertible): Diagnosis Volvo C70 I

Camshaft diagnostics

The task of the variable camshaft is to alter the camshaft position to minimize emissions and optimize the engine performance. The camshaft displacement in relation to the crankshaft is calculated using the engine load and engine speed (RPM).

The diagnostic consists of 4 parts

1. When the ignition is switched on, an electrical check is carried out on the signal cable, the power supply cable and the solenoid. The check is for a short-circuit to supply voltage / ground and open-circuit. This diagnostic is switched off when the engine is running
2. When the camshaft is in its 0 position (mechanical resting position), it is checked to see if it is in the correct position compared to the flywheel. If the deviation is excessive the variable camshaft is switched off
3. In case of larger controlled deviations at the variable camshaft the time taken to regulate to the control value is measured. This time is used partially to determine how long it takes to alter the camshaft angle and partially to switch off the variable camshaft if the time exceeds a certain maximum time. The information about the speed at which the camshaft angle changes is used in the control strategy. The camshaft uses the engine oil and oil pressure to turn. The turning time depends on oil pressure, viscosity etc. which in turn depends on oil temperature and quality etc.
4. The camshaft position (CMP) sensor is compared with the flywheel sensor to check if the camshaft position (CMP) sensor detects all lobes.

The mechanical 0 position depends on the engine type

For turbocharged engines the camshaft mechanical 0 position is in the performance position.

For 6 cylinder naturally aspirated engines the camshaft mechanical 0 position is the low speed position.

For 5 cylinder naturally aspirated engines the camshaft mechanical 0 position is the low speed position.

Connecting Driver Information Module (DIM) test box

Special tools

9511463

9511428

9511499

9813190

Scheme 156

1. Ignition off
2. Remove interior fuse 24 (11C/24)
3. Loosen the combined instrument as described in «Driver information module (DIM), replacing»(ref-404026-S24866906602011061000000)
4. Release control unit connector.

Connect adapter 9511463 (22-16-14-pin) to control unit connector and connect test box 9511428 and wire 9511499 to adapter.

Alternatively connect test box 9813190 to adapter.

Disconnect the test box in the reverse order.

Scheme 157

Additional information

1. To remove the combined instrument see «Driver information module (DIM), replacing»(ref-404026-S24866906602011061000000)
2. For information about signals and other values, see «Driver Information Module (DIM) signal description»(ref-404026-S28195092972011061000000) .

Fuel tank system quick test

Shows the current status of the quick test (In progress/Not in progress)

Test phase

Shows the current phase of the leak diagnosis. For more information, see "Test phases, quick test tank system".

DMTL, test result

Shows the test result on the leak diagnostic unit (DMTL).

If "Fault found" is shown, the Engine control module (ECM) has generated a diagnostic trouble code (DTC) for the fault. Fault tracing should be started/continued.

Tank system, test result

Shows the test result for the fuel tank system.

If "Minor leak found" or "Major leak found" is shown the Engine control module (ECM) has generated a diagnostic trouble code (DTC) for the fault. Fault tracing should be started/continued.