Engine Control Module (ECM) Diagnostic Trouble Codes - 12 of 13: Wiring Volvo XC90 I

CHECKING COMPONENTS AND WIRING

1. Ignition off Check the auxiliaries belt and belt tensioner for damage. Check the function of the alternator freewheel. A fault-free freewheel pulls around the alternator rotor shaft in one direction but not the other. HINT: If the diagnostic trouble code recurs after operation, try a new alternator.

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1. Start and warm up the engine. Read off the fuel pump's load (signal from engine control module (ECM) to fuel pump module). Check that the signal is approx. 50 % (±10 %) for idling, warm engine. Check the cable between engine control module (ECM) #B20 (#C20) and fuel pump module #1 for short-circuit to ground, as well as open circuit. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «CONTROL MODULE FUEL PUMP (FP), REPLACING»(ref-476695-S09602766612012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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1. Start and warm up the engine. Read off the fuel pump's load (signal from engine control module (ECM) to fuel pump module). Check that the signal is approx. 50 % (±10 %) for idling, warm engine. Check the cable between engine control module (ECM) #B20 (#C20) and fuel pump module #1 for short-circuit to voltage. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «FUEL PUMP DRIVER MODULE»(ref-476695-S02740070142012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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1. Start and warm up the engine. Read off the fuel pump's load (signal from engine control module (ECM) to fuel pump module). Check that the signal is approx. 50 % (±10 %) for idling, warm engine. Check the cable between engine control module (ECM) #B20 (#C20) and fuel pump module #1 for short-circuit to voltage. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «CONTROL MODULE FUEL PUMP (FP), REPLACING»(ref-476695-S09602766612012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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1. Ignition off Check the signal cable for short-circuit to voltage. Check between: Engine control module (ECM) #B53 (#C53) and A/C relay's connector #4, signal cable (+). Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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1. Ignition off Check the control valve between control valve terminals #1 and #2. Check the resistance. Disconnect the engine control module (ECM). Check the signal cable for the control valve. Check for a short-circuit to supply. Take readings between control module terminal #A95 (#B35) and control valve terminal #2. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «COMPONENT SPECIFICATIONS»(ref-476694-S25047767552012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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CHECKING THE COMPONENT AND WIRING

Check if there is voltage in the system relay's socket #87(3). System relay's socket #87(3) shall be without voltage.

If there is voltage on the system relay's socket #87(3), then check connections and branchings from the socket's #87(3) for short-circuiting to voltage.

HINT: The system relay #30(1) is connected to kl:30 and #87(3) is the output.

Remedy as necessary.

Other information

1. see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000)
2. see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000)
3. see «REPLACING RELAYS IN THE MAIN FUSE BOX AND OTHER RELAYS IN THE ENGINE COMPARTMENT»(ref-494831-S34323336502012081600000)

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1. Ignition off.
2. Remove the system relay. Check the relay for short-circuiting between #30(3) and #86(1). HINT: When the relay is not drawn, there shall be open circuit between the system relay's #30(3) and #86(1). If not open circuit, the relay is damaged. Check the signal cable between the system relay's socket #85(2) and Engine Control Module (ECM) #B16 (#C16) for short-circuiting to ground. HINT: Check the signal cable between the system relay's socket #85(2) and Engine Control Module (ECM) #B16 (#C16) for short-circuiting to ground. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S30437390172012060500000) see «SIGNAL SPECIFICATION»(ref-476694-S14228516802012060500000) see «CENTRAL ELECTRICAL UNIT ENGINE COMPARTMENT, REPLACING»(ref-476708-S33348883502012060500000)

Has the fault been remedied?

1. YES Refer to «VERIFICATION»(ref-476784-S39576306772012060500000)
2. NO Refer to «CHECKING THE COMPONENT AND WIRING»(ref-476784-S26908339022012060500000)

Check if there is voltage in the system relay's socket #87(5). System relay's socket #87(5) should not be voltage fed.

If there is voltage on the system relay's socket #87(5), check connections and branchings from the socket's #87(5) for short-circuiting to voltage.

HINT: The system relay #30(3) is connected to kl:30 and #87(5) is the output.

Remedy as necessary.

Other information

1. see «CONNECTING THE BREAKOUT BOX»(ref-476691-S30437390172012060500000)
2. see «SIGNAL SPECIFICATION»(ref-476694-S14228516802012060500000)
3. see «CENTRAL ELECTRICAL UNIT ENGINE COMPARTMENT, REPLACING»(ref-476708-S33348883502012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S39576306772012060500000)

1. Ignition off
2. Disconnect the engine control module (ECM). Check the signal cable. Check for a short-circuit to supply voltage. Check between: Control module #B49 (#B59) and engine cooling fan #4. Activate the engine cooling fan using the VCT2000 (or appropriate scan tool). Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

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1. Ignition on Activate readout of brake pedal position (via CAN) and position of the brake light switch. Check that the value for brake pedal position at unaffected brake pedal is approx. 0 % and when the pedal is fully pressed down approx. 55 % when the engine is running. Also check that the brake light switch is activated when the pedal is pressed down. Check the connector for the brake pedal position sensor and the brake light switch for contact resistance, loose connections and oxidation. Check the ground cable between brake light switch and engine control module (ECM) #B41 (#C41) for short-circuit to ground, as well as open circuit. HINT: The brake pedal position sensor's signal is sent to engine control module (ECM) from brake control module (BCM) via CAN. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «PEDAL POSITION SENSOR, REPLACING»(ref-476785-S37121877352012060500000) see «STOP LAMP SWITCH, REPLACING»(ref-476779-S00282256302012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S01929968732012060500000)

1. Ignition off Check engine control module ECM) and the electronic throttle unit's connector for contact resistance and oxidation. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «THROTTLE BODY (ELECTRONIC THROTTLE MODULE (ETM)), REPLACING»(ref-476768-S25810669542012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S42867767752012060500000)

1. Ignition off Check engine control module ECM) and the electronic throttle unit's connector for contact resistance and oxidation. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S30437390172012060500000) see «SIGNAL SPECIFICATION»(ref-476694-S14228516802012060500000) see «THROTTLE BODY»(ref-476768-S33718197072012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S25319994792012060500000)

HINT: If diagnostic trouble code for gear position sensor is stored in transmission control module (TCM), then troubleshoot this diagnostic trouble code first.

1. Check transmission control module (TCM) connector for contact resistance and oxidation. Check the signal cable for open circuit, short-circuit to voltage and short-circuit to ground. Measure between engine control module (ECM) #B15 (#C15) and transmission control module (TCM) #5. Remedy as necessary. HINT: Read off the gear position sensor's signals using the VCT2000 (or appropriate scan tool). Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S13209831052012060500000)

1. Ignition off Check relevant connectors for loose connections, contact resistance and oxidation. Check the signal cables and the ground cable for short-circuit to voltage and open circuit. Check between: The control module #B5 (#A65) and electronic throttle unit's connector #6, signal cable position sensor 1. The control module #B7 (#A67) and electronic throttle unit's connector #4, signal cable position sensor 2. The control module #A11 (#A11) and electronic throttle unit's connector #3, ground. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «THROTTLE BODY (ELECTRONIC THROTTLE MODULE (ETM)), REPLACING»(ref-476768-S25810669542012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S12336232822012060500000)

1. Ignition off Check relevant connectors for loose connections, contact resistance and oxidation. Check the signal cables for short-circuit to ground as well as open circuit. Check the voltage feed for short-circuit to ground. Check between: The control module #B5 (#A65) and electronic throttle unit's connector #6, signal cable position sensor 1. The control module #B7 (#A67) and electronic throttle unit's connector #4, signal cable position sensor 2. The control module #A11 (#A11) and electronic throttle unit's connector #3, ground. The control module #A24 (#A24) and electronic throttle unit's connector #5, voltage feed. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «THROTTLE BODY (ELECTRONIC THROTTLE MODULE (ETM)), REPLACING»(ref-476768-S25810669542012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S29289652712012060500000)

Check the voltage on throttle unit connector #3 to the system relay. The voltage must be approximately battery voltage when the ignition is on.

Check signal cable for an open-circuit and short-circuit to supply voltage.

Take readings between

1. Engine control module (ECM) terminal #A38 (#A38) and throttle unit terminal #1.

Remedy as necessary.

Other information

1. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S35489146962012060500000)

Check the function of the control valve (2) by activating it. The valve should click on activation.

Connect a vacuum pump to the control valve's terminal (for hose connected to the intake manifold) and pump to create a vacuum. Listen for leakage and check the pump's gauge for stable pressure. If the pressure drops, this means a leaking valve.

Check that the dampers (4) can move freely and that nothing is obstructing them.

HINT: Check the function by pumping a vacuum to the vacuum motor.

Remedy as necessary.

Other information

1. For control valve replacement: «DISTRIBUTION DAMPER INTAKE PIPE, REPLACING»(ref-476768-S32575538702012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S22377460012012060500000)

Check the voltage on throttle unit connector #3 to the system relay. The voltage must be approximately battery voltage when the ignition is on.

Check signal cable for an open-circuit and short-circuit to supply voltage.

Take readings between

1. Engine control module (ECM) terminal #A39 (#A39) and throttle unit terminal #1.

Remedy as necessary.

Other information

1. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S00288243542012060500000)

Activate the control valve (2) to check its function. The valve must click at activation.

Connect a vacuum pump to the control valve terminal (for hoses connected to the intake manifold) and pump a vacuum. Listen for leakage. Check the stability of the pressure on the gauge. The valve is leaking if the pressure drops.

Check the vacuum hoses for leakage and blockages between

1. the intake manifold and the vacuum tank (1)
2. the vacuum tank (1) and the control valve(2)
3. the control valve (2) and the vacuum motor (3)

Check that all vacuum hoses are correctly connected on the above components.

Check that the dampers (4) can move freely and that nothing is obstructing them.

HINT: Check the function by pumping a vacuum to the vacuum motor.

Remedy as necessary.

Other information

1. For control valve replacement: «DISTRIBUTION DAMPER INTAKE PIPE, REPLACING»(ref-476768-S32575538702012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S11118125222012060500000)

Check connector for contact resistance and oxidation.

Check voltage feed between engine control module (ECM) #B32 (#C32) and accelerator pedal position sensor #6.

Check the ground cable between engine control module (ECM) #B7 (#C7) and accelerator pedal position sensor #4.

Check the cable between engine control module (ECM) #B28 (#C28) and accelerator pedal position sensor #2.

Remedy as necessary.

Other information

1. see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000)
2. see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000)
3. For replacing accelerator pedal position sensor: «ACCELERATOR PEDAL (AP), REPLACING»(ref-476780-S18973143032012060500000)
4. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

Scheme 427

1. Continue Refer to «VERIFICATION»(ref-476784-S27328508982012060500000)

CHECKING THE COMPONENTS AND WIRING

Note. Check if other diagnostic trouble codes (DTCs) are stored for the internal atmospheric pressure sensor or if diagnostic trouble codes (DTCs) for the air pressure sensor in the inlet manifold are stored in the Engine Control Module (ECM). These diagnostic trouble codes (DTCs) must be fault-traced and any faults remedied first.

1. Ignition on. Activate reading the value from the manifold absolute pressure (MAP) sensor and the atmospheric pressure sensor. Check the difference between pressures, the difference shall not be greater than 70 hPa. HINT: Normal atmospheric pressure is 1013 hPa. Check cables and connectors to the air pressure sensor inlet for contact resistance or oxidation, short-circuit to ground and voltage as well as open circuit. Remedy as necessary. Try with a new air pressure sensor. Check the difference between pressures, the difference shall not be greater than 70 hPa. When the difference between the pressures is greater than 70 hPa this indicates that the internal atmospheric pressure sensor in the engine control module (ECM) is damaged. The atmospheric pressure sensor is built into the engine control module (ECM) and therefore cannot be replaced as a separate item. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S27857399862012060500000) see «SIGNAL SPECIFICATION, ENGINE CONTROL MODULE (ECM)»(ref-476694-S30016655152012060500000) see «LOCATION OF COMPONENTS, ENGINE COMPARTMENT»(ref-476766-S16137402102012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000) see «ENGINE CONTROL MODULE (ECM), REPLACING»(ref-476695-S24530329132012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S07861920792012060500000)

Note. Check if other diagnostic trouble codes (DTCs) are stored for the internal atmospheric pressure sensor or if diagnostic trouble codes (DTCs) for the air pressure sensor in the inlet manifold are stored in the Engine Control Module (ECM). These diagnostic trouble codes (DTCs) must be fault-traced and any faults remedied first.

1. Ignition on. Activate reading the value from the manifold absolute pressure (MAP) sensor and the atmospheric pressure sensor. Check the difference between pressures, the difference shall not be greater than 70 hPa. HINT: Normal atmospheric pressure is 1013 hPa. Check cables and connectors to the air pressure sensor inlet for contact resistance or oxidation, short-circuit to ground and voltage as well as open circuit. Remedy as necessary. Try with a new air pressure sensor. Check the difference between pressures, the difference shall not be greater than 70 hPa. When the difference between the pressures is greater than 70 hPa this indicates that the internal atmospheric pressure sensor in the engine control module (ECM) is damaged. The atmospheric pressure sensor is built into the engine control module (ECM) and therefore cannot be replaced as a separate item. Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S30437390172012060500000) see «SIGNAL SPECIFICATION»(ref-476694-S14228516802012060500000) see «LOCATION OF COMPONENTS»(ref-476766-S34089063632012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000) see «ENGINE CONTROL MODULE (ECM), REPLACING»(ref-476695-S24530329132012060500000)

1. Continue Refer to «VERIFICATION»(ref-476784-S04220869872012060500000)