Sonata V6-3.0L (1991)
Voltage Regulator: All Technical Service Bulletins
Voltage Regulator - Overcharge Condition
Group: ENGINE ELECTRICAL
Number: 93-36-014
Date: OCTOBER, 1993
Model: ALL
Subject:
VOLTAGE REGULATOR OPERATION
This TSB provides information concerning the diagnosis and repair of voltage regulator related conditions
All Hyundai vehicles utilize a solid state voltage regulator which is an integral part of the alternator assembly. An overcharge condition may result from
a voltage regulator malfunction and may damage electronic components including:
-
Light bulbs
-
Fusible link(s) or fuses
-
Engine Control Module (ECM)
-
Transmission Control Module (TCM)
-
TACU/ETACS Modules
-
Radio
Multiple blown light bulbs and/or a blown fusible link(s) are indications that a voltage regulator overcharge condition has occurred. In the most severe
case, a no-start complaint may occur as a result of ECM damage.
NOTE:
If a voltage regulator malfunction is suspected, DO NOT connect the MUT tester to the vehicle with the vehicle running or damage to the MUT
tester may occur.
CONDITION # 1 (NO CRANK, NO START):
If a customer complains of a no-crank, no start condition, perform the following steps:
1)
Verify the condition of the main fusible link (located on the positive battery terminal), and other fusible links (in the engine compartment
relay box). Replace as necessary.
2)
Verify the operation of all light bulbs.
3)
Connect the MUT to the vehicle's diagnostic connector and turn the ignition key to the "ON" position. If the MUT displays a "Can't Comm"
message when attempting to view the "Trouble Codes" or "Service Data" screen, it is possible the ECM has been damaged by an overcharge
condition.
If an overcharge condition is suspected after performing the above steps, the alternator should be removed and bench tested to verify proper regulator
operation.
If an overcharge condition is identified, the operation of all electrical circuits should be verified following alternator replacement.
CONDITION # 2 (OVERCHARGE SYMPTOMS PRESENT, VEHICLE RUNS):
If an overcharge condition is suspected and the vehicle will start, follow the procedure below to verity voltage regulator operation:
1.
Before testing the voltage regulator, ensure:
a)
The battery is fully charged (see "Battery" under the "Engine Electrical System - Charging System' section of the shop manual).
b)
The alternator belt tension is correct (see "Drive Belt Tension Adjustment" in the "Cooling System" section of the shop manual.
c)
The battery cables are in good condition, and the cable connections are clean and tight
d)
The 2 PIN (lands) connector to the alternator is secure.
2.
Turn all lights and accessories (blower fan, radio, etc.) off. Start the vehicle's engine.
3.
Connect the positive lead of a digital voltmeter to the alternator's "B+" terminal; connect the negative lead to the battery ground (-) terminal.
The voltage should read approximately 14 volts.
4.
Slowly increase the rpm of the engine to 2500 rpm while monitoring the voltmeter. If the voltage reading rises above 15.5 volts, decrease
the engine rpm and turn the ignition switch off. A reading greater than 15.5 volts indicates a voltage regulator condition requiring
replacement of the alternator assembly.
