Inspection and verification
CAUTION: Diagnostics by substituting a component from another vehicle is PROHIBITED. Substituting control units does not guarantee confirmation of the fault and, in addition, may cause additional faults in the vehicle being tested 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 charge level of the vehicle battery before diagnosing any component of the charging system as faulty. Refer to the battery care guide for more information.
For a complete list of diagnostic trouble codes that may be stored in the vehicle, see Section 100-00. For additional information, refer to: (100-00 General information) Diagnostic Trouble Code (DTC) Index - Engine Control Module (PCM) Trouble Code (Description and principle of operation), Diagnostic Trouble Code (DTC) Index - Instrument Cluster (IPC) Trouble Code (Description and principle of operation).
External examination
|
Mechanical |
Electric |
|
• Generator • Drive belt • Drive belt tensioner • Generator pulley • Check the reliability of the generator mounting elements |
• Generator • Battery • Mega-fuse • Engine/generator ground connection • Wiring harness(es) • Electrical connector(s) • Engine Control Module (ECM) • Central distribution box (only Freelander 2) |
3. If an obvious cause for the problem you identified or the customer described is found, resolve it before moving on to further action (if possible).
4. If the cause is not visually obvious, check for DTCs and refer to the Diagnostic Trouble Code (DTC) Index.
DTC Index
NOTE: If a control module or component is suspected and the vehicle is still under manufacturer 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 effect.
NOTE: Generic scan tools cannot read the codes listed or can only read 5-digit codes. To identify the fault, match the five digits from the scan tool to the first five digits of the listed 7-digit code (the last 2 digits provide additional information readable by a manufacturer approved diagnostic system).
NOTE: When performing voltage or resistance tests, always use a digital multimeter (DMM) with three decimal places of accuracy and a current calibration certificate. When testing resistance, always include the resistance of the DMM leads.
NOTE: Before starting diagnostic programs using fault location tests, check and correct basic faults.
NOTE: If DTCs are set and the fault is not present after performing the troubleshooting tests, an intermittent problem may be the cause. Be sure to check for loose connections and corroded terminals.
| Sign | Possible reason | Actions taken |
| The charging indicator does not light up | ||
| The charging indicator light stays on/the battery is discharging. | ||
| Periodic activation of the charging indicator | NOTE: Using a portable power supply or jump starter may cause the alarm to sound before the devices are turned off | |
| The battery is discharged, but the charging indicator does not light | ||
| Noise (mechanical) | Accessory drive belt slippage |
|
PINPOINT TEST A: BLOCK DIAGRAM FOR DIAGNOSTICS OF BOSCH GENERATOR WITHOUT BMS |
|
|
STATES! details/results/actions |
|
|
A1: CHECKING MIDTRONICS BATTERY |
|
|
NOTE: Before diagnosing the alternator, the battery must be fully charged and all battery faults must be corrected |
|
|
NOTE |
: The voltmeter must be accurate to three decimal places (for example 0.001 V) |
|
NOTE |
: Ignition on - position 2 in the ignition system with a key |
|
NOTE |
: Turn 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 the "Midtronics Battery Check" as described in the battery care manual. For more information, please refer to: Battery Care (414-00 Battery and charging system - General information, Description and operating principle). |
|
|
2 Record the battery diagnostic result in the form provided |
|
|
Did the battery pass the "Midtronics Battery Test"? Да GO to B1. No Before diagnosing the alternator, troubleshoot all battery problems. Proceed to PINPOINT TEST B. |
|
|
PINPOINT TEST B: BLOCK DIAGRAM FOR DIAGNOSTICS OF BOSCH GENERATOR WITHOUT BMS |
|
|
STATES! details/results/actions |
|
|
B1: GENERATOR OUTPUT |
|
|
NOTE: Freelander 2 = Rear heated window timer set to 12 minutes |
|
|
NOTE: Defender = Rear heated window timer set to 8 minutes |
|
|
1 Connect the voltmeter to the car battery |
|
|
2 Turn on the ignition (the engine is not working) |
|
|
3 Turn off all electrical consumers (for example, a fan, radio, interior lighting, etc.) |
|
|
4 Start the engine, turn on the rear window heating • Make sure the rear window heating is onюchen (see note above), and the air conditioning system is offюchena. |
|
|
5 Wait 90 seconds |
|
|
6 Record the battery voltage (V1) according to the multimeter reading |
|
|
Battery voltage at idle (V1) = 14.8 V or higher? Да Install a new generator. Before installing a new unit/element, consult your warranty and procedures manual to determine if the replacement requires pre-authorization under any applicable special program No GO to B2. |
|
|
B2: BATTERY IDLE VOLTAGE |
|
|
1 Based on the battery voltage reading (V1) |
|
|
Battery voltage at idle (V1) = 13V or higher(but below 14.8 V)? Yes GO to B3. No Proceed to PINPOINT TEST C. |
|
|
B3: BATTERY ALARM |
|
|
1 Battery voltage at idle speed (V1) = 13 V or higher(but below 14.8 V)? |
|
|
Is the battery indicator light on? Да Proceed to PINPOINT TEST C. No Generator output is within expected range, do not replace the generator. If the fault reported by the customer is still evident, contact the dealer technical support |
|
|
PINPOINT TEST C: BLOCK DIAGRAM FOR DIAGNOSTICS OF BOSCH GENERATOR WITHOUT BMS |
|
STATES! details/results/actions |
|
C1: CHECKS OF CIRCUIT |
|
NOTE: Freelander 2 = Charge indicator controlled by central junction box (from the powertrain control unit), connected to the instrument panel unit via the CAN bus |
|
NOTE: Defender = The charge indicator is controlled by the powertrain control unit, which is connected to the instrument cluster unit via the CAN bus |
|
|
1 Freelander 2 = Using the electrical circuit diagrams, check the circuit (LIN) between generator and engine control unit for short circuit to ground/power supply, open circuit and high resistance |
|
|
2 Defender = Using the electrical diagrams, check the circuits (D+ and ALTMON) between the alternator and the ECM for short to ground/power, open circuit and high resistance |
|
|
Are there any obvious faults in the circuit? Да Repair circuit if necessary Proceed to PINPOINT TEST B. No Proceed to PINPOINT TEST D. |
|
|
PINPOINT TEST D: BLOCK DIAGRAM FOR DIAGNOSTICS OF BOSCH GENERATOR WITHOUT BMS |
|
|
STATES! details/results/actions |
|
|
D1: CHECKING CIRCUIT 1 |
|
|
NOTE: Freelander 2 = Rear heated window timer set to 12 minutes |
|
|
NOTE: Defender = Rear heated window timer set to 8 minutes |
|
|
1 Connect the voltmeter to the car battery |
|
|
2 Turn on the ignition (the engine is not working) |
|
|
3 Turn off all electrical consumers (for example, a fan, radio, interior lighting, etc.) |
|
|
4 Start the engine, turn on the rear window heating • Make sure the rear window heating is onюchen (see note above), and the air conditioning system is offюchena. |
|
|
5 Voltage measurement • Measure the voltage drop between the generator housing and the negative terminal of the battery and record the obtained value (V2) |
|
|
The obtained voltage drop value (V2) = less than 0.3 V? Да GO to D2. No Turn off the engine. Circuit check. Using the electrical diagrams, check the alternator housing and negative battery cables for loose or corroded connections. Repair any circuit faults and retest the alternator. Go to PINPOINT TEST B. |
|
|
D2: CHECKS CIRCUIT 2 |
|
|
1 Voltage measurements • Measure the voltage difference between the B+ terminal of the generator and the positive terminal of the battery and record the obtained value (V3) |
|
|
The obtained voltage drop value (V3) = less than 0.3 V? Да Install a new generator. Before installing a new unit/element, consult your warranty and procedures manual to determine if the replacement requires pre-authorization under any applicable special program No Turn off the engine. Circuit Check. Using the electrical diagrams, check the alternator B+ terminal and the positive battery cables for loose or corroded connections. Repair any circuit faults and retest the alternator. Go to PINPOINT TEST B. |
|
Comments on this article