Inspection and verification
WARNING: Diagnosis by substituting a component from another vehicle is FORBIDDEN. The substitution of control units does not guarantee confirmation of the fault and, moreover, may cause additional faults in the tested vehicle and/or in the vehicle from which the modules are removed.
1. Check the validity of the customer's complaint.
2. Perform a visual inspection for obvious mechanical or electrical damage.
NOTE: Check the condition and level of charge of the vehicle's battery before admitting any element of the charging system is faulty. For more information, see the Battery Care Guide.
See section 100-00 for a complete list of DTCs that can be logged in the vehicle. For more information, please refer to: (100-00 General information) Index of diagnostic trouble codes (DTC) - Engine Control Module Fault Code (PCM) (Description and principle of operation), Index of diagnostic trouble codes (DTC) - Fault code Instrument Cluster (IPC) (Description and principle of operation).
External examination
Mechanical |
Electric |
• Generator • Drive belt • Drive belt tensioner • Alternator pulley • Check the reliability of the fastening elements of the generator |
• Generator • Battery • Mega-fuse • Engine/generator ground connection • Harness (s) electrical wiring • Electric (e) connector (s) • The engine control unit (ECM) • Central junction box (Freelander 2 only) |
3. If an obvious cause of a problem you identified or described by a customer is found, resolve it before proceeding to the next steps (if possible).
4. If the cause is not visually obvious, check for DTCs and refer to the Diagnostic Trouble Code Index (DTC).
DTC index
NOTE: If a control module or component is suspected and the vehicle continues to be covered by the manufacturer's warranty, refer to the warranty manual before installing a new module/component (subsection B1.2), or determine if there is any previously approved special program in operation.
NOTE: Universal Scan Tools cannot read the listed codes or can only read 5-digit codes. To identify the problem, match the five digits from the scan tool with the first five digits of the seven-digit code listed (the last 2 digits give additional information read by the diagnostic system approved by the manufacturer).
NOTE: Always use a digital multimeter when performing voltage or resistance tests (DMM) accurate to three decimal places and with a modern calibration certificate. When testing resistance, always consider the resistance of the DMM wires.
NOTE: Before starting diagnostic programs using troubleshooting tests, check and correct major problems.
NOTE: If DTCs are logged and there is no problem after performing troubleshooting tests, an intermittent problem may be the cause. Be sure to check for loose connections and corroded contacts.
sign | Possible reason | Actions taken |
Charging indicator does not light up | ||
Charging indicator stays on/battery is discharging. | ||
Periodic activation of the charging indicator | NOTE: The use of a portable power supply or a starter charger may cause the alarm to go off until the devices are turned off | |
The battery is discharging, but the charging indicator does not light up | ||
Noise (mechanical) | Accessory Drive Belt Slip |
PINPOINT TEST A: BOSCH GENERATOR DIAGNOSIS FLOW DIAGRAM WITHOUT BMS |
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CONDITIONS! details/results/actions |
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A1: CHECK MIDTRONICS BATTERY |
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NOTE: The battery must be fully charged and all battery faults must be repaired prior to starting alternator diagnostics |
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NOTE |
: Voltmeter must be accurate to three decimal places (e.g. 0.001 V) |
NOTE |
: Switching on the ignition - position 2 in the ignition system with the key |
NOTE |
: Switching on the ignition - two short presses of the start button (power mode 6) with keyless ignition system |
1 Using the Midtronics Handheld Tester or the Midtronics GR-1 Diagnostic Charger, perform "Midtronics battery test" according to the instructions in the battery care manual. For more information, refer to: Caring for your battery (414-00 Battery and charging system - General information, Description and principle of operation). |
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2 Record the result of battery diagnostics in the form provided for this |
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Has the battery gone "Midtronics battery test"? Yes GO to B1. No Troubleshoot the battery before diagnosing the alternator Go to PINPOINT TEST B. |
PINPOINT TEST B: BOSCH GENERATOR DIAGNOSIS FLOW CHART WITHOUT BMS |
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CONDITIONS! details/results/actions |
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B1: GENERATOR OUTPUT |
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NOTE: Freelander 2 = Heated rear window timer set to 12 minutes |
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NOTE: Defender = Heated rear window timer set to 8 minutes |
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1 Connect a voltmeter to the car battery |
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2 Turn on the ignition (engine not running) |
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3 Turn off all electrical consumers (e.g. fan, radio, indoor lighting, etc.) |
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4 Start the engine, turn on the heated rear window • Make sure the heated rear window is on yuchen (see note above), and the air conditioning system off yu chen. |
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5 Wait 90 seconds |
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6 Record the battery voltage (V1) according to the multimeter |
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Battery voltage at idle (V1) = 14.8 V or higher? Yes Install a new generator. Before installing a new unit/element, refer to the Warranty and Procedures Manual to determine if a replacement requires prior authorization under any applicable special program No GO to B2. |
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B2: BATTERY VOLTAGE AT IDLE |
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1 Based on battery voltage reading (V1) |
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Battery voltage at idle (V1) = 13 V or higher (but below 14.8 V)? Yes GO to B3. No Go to PINPOINT TEST C. |
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B3: Battery alarm |
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1 Battery voltage at idle (V1) = 13 V or higher (but below 14.8V)? |
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Is the battery warning light on? Yes Go to PINPOINT TEST C. No Alternator output is within expected range, do not replace alternator. If the problem reported by the customer is still evident, contact the dealer's technical support |
PINPOINT TEST C: BOSCH GENERATOR DIAGNOSIS FLOW CHART WITHOUT BMS |
STATUS! details/results/actions |
C1: CIRCUITS TESTS |
NOTE: Freelander 2 = Charge alarm controlled by central junction box (from the powertrain control unit), connected to the instrument panel unit via the CAN bus |
NOTE: Defender = Charge warning light is controlled by the powertrain control module connected to the instrument cluster via the CAN bus |
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1 Freelander 2 = Refer to electrical circuit diagrams and check circuit (LIN) between generator and engine control unit for a short circuit to "mass"/ power circuit, open circuit and high resistance |
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2 Defender = Refer to electrical circuit diagrams and check circuits (D+ and ALTMON) between the generator and the engine control unit for a short circuit to "mass"/ power circuit, open circuit and high resistance |
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Are there any obvious circuit faults? Yes Repair circuit if necessary Go to PINPOINT TEST B. No Go to PINPOINT TEST D. |
PINPOINT TEST D: BOSCH GENERATOR DIAGNOSIS FLOW CHART WITHOUT BMS |
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CONDITIONS! details/results/actions |
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D1: CIRCUIT 1 TESTS |
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NOTE: Freelander 2 = Heated rear window timer set to 12 minutes |
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NOTE: Defender = Heated rear window timer set to 8 minutes |
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1 Connect a voltmeter to the car battery |
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2 Turn on the ignition (engine not running) |
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3 Turn off all electrical consumers (e.g. fan, radio, indoor lighting, etc.) |
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4 Start the engine, turn on the heated rear window • Make sure the heated rear window is on yuchen (see note above), and the air conditioning system off yu chen. |
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5 Voltage measurement • Measure the voltage drop between the alternator case and the negative battery terminal and record the value (V2) |
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The resulting value of the voltage drop (V2) = less than 0.3 V? Yes GO to D2. No Turn off the engine. Circuit check. Refer to electrical circuit diagrams and check alternator case and negative battery cables for loose or corroded connectors. Repair any circuit faults and retest the alternator Go to PINPOINT TEST B. |
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D2: CIRCUIT 2 CHECKS |
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1 Voltage measurements • Measure the voltage drop between the alternator B+ terminal and the positive battery terminal and record the value (V3) |
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The resulting value of the voltage drop (V3) = less than 0.3 V? Yes Install a new generator. Before installing a new unit/element, refer to the Warranty and Procedures Manual to determine if a replacement requires prior authorization under any applicable special program No Turn off the engine. Circuit check. Refer to the electrical circuit diagrams and check alternator B+ terminal and positive battery cables for loose or corroded connectors. Repair any circuit faults and retest the alternator Go to PINPOINT TEST B. |
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