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System Testing

Following VOLTAGE CHECKS and RESISTANCE CHECKS charts show procedure for checking CIS-E system components from ECU connector. ECU connector terminal numbers are called out in testing procedures. Ignition MUST be off whenever ECU connector is disconnected or reconnected. Use care to avoid any terminal damage when testing, removing or attaching connectors.

Always check all connections used in test procedure. If readings are incorrect, disconnect terminals and determine if wiring or components are at fault. High tension lead should be disconnected at ignition distributor end and connected to ground. Use Digital Multimeter (US 1119).

QUANTUM 5-CYLINDER VOLTAGE CHECKS (1)

Voltmeter Between Terminals Components Checked Specifications
No. 1 & No. 2 Voltage Supply To ECU Battery voltage with ignition on. If not check fuse 24. If good check open ground circuit between intake manifold & ECU.
No. 2 & No. 24 Voltage Supply From Starter Minimum reading of 8 volts w/starter cranking. If not check wiring from starter to ECU. If wiring good check starter solenoid.
(1) TESTING CONDITIONS : Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20 volts DC scale.
QUANTUM 4-CYLINDER, GOLF & JETTA VOLTAGE CHECKS (1)

Voltmeter Between Terminals Components Checked Specifications
No. 1 & No. 2 Voltage Supply To ECU Battery voltage with ignition on. If not check fuse 18. If good check open ground circuit between intake manifold and ECU.
No. 1 & No. 2 Voltage Supply From Starter Minimum 8 volts with starter cranking. If not, check wiring to 15 and "X" terminals reversed on relay board. See wiring diagram.
No. 2 & No. 24 Wire From Starter To ECU Minimum 8 volts with starter cranking. If not, line 24 is open. If wiring good, check starter solenoid.
(1) TESTING CONDITIONS: Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20-volt DC scale.
GLI & GTI RESISTANCE CHECKS (1)

Ohmmeter Between Terminals Components Checked Specifications
No. 2 & No. 7 O(2) Sensor Wire Shield Ground Reading should be zero ohms. If not, check ground point at intake manifold.
No. 2 & No. 9 M/T Ground Reading should be zero ohms. If not, check ground point at intake manifold.
No. 2 & No. 15 Ground Cable Bridge Reading should be zero ohms. If not, check ground point at intake manifold.
No. 2 & No. 22 A/T Ground Reading should be zero ohms. If not, check ground point at intake manifold.
No. 2 & No. 20 Battery Ground Reading should be zero ohms. If not, check cable to battery negative terminal.
No. 2 & No. 8 O(2) Sensor & Wiring Reading should be zero ohms with Green O(2) sensor lead unplugged and grounded. If not, check Green wire for open. Reading should be infinity ohms with O(2) sensor lead connected. If not, O(2) sensor is defective and should be replaced.
No. 11 Altitude Sensor (2)
No. 10 & No. 12 Differential Pressure Reg. & Wiring Reading should be 17.5-21.5 ohms. If not, wire 10 or 12 is is open. If wiring is good, differential press regulator is defective and should be replaced.
No. 14 & No. 17 Potentiometer & Wiring (3) Reading of more than 4-k/ohms with airflow sensor plate lifted away from rest position. If not, check wires 14, 17 and 18 for open. If wires are good, adjust or replace Potentiometer.
No. 17 & No. 18 Potentiometer & Wiring (3) Reading of less than 1000 ohms with airflow sensor plate in rest position. If not, check 14, 17 and 18 for open. If wires are good, adjust or replace potentiometer.
No. 21 & No. 2 Temperature Sensor Reading of 2.5-k/ohms at 68°F (20°C). Resistance reading should be higher at lower temperatures and lower at higher temperatures. If not, check for open circuit in wiring. If wiring is good, replace temperature sensor.
(1) - TESTING CONDITIONS: Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20,000-ohm scale. Prevent ohmmeter damage by checking ONLY terminals listed.
(2) No specifications given for testing altitude sensor, if equipped.
(3) Potentiometer terminals No. 1, 2 and 3 are connected respectively to terminals No. 18, 17 and 14 on ECU connector.
QUANTUM 5-CYLINDER RESISTANCE CHECKS (1)

Ohmmeter Between Terminals Components Checked Specifications
No. 2 & No. 22 Ground Bridge Reading of 0 ohms.If not check for open in bridge across terminals.
No. 2 & No. 15 Ground Bridge Reading of 0 ohms.If not check for open in bridge across terminals.
No. 7 & No. 8 O2 Sensor Wire Reading of infinity ohms. If not check for open circuit in O2 sensor lead.
No. 2 & No. 8 O2 Sensor Wiring Reading of 0 ohms w/ Green O2 sensor lead unplugged grounded If not check for open in circuit in Green O2 sensor lead.
No. 10 & No. 12 Differential Pressure Reg. & Wiring Reading of 17.5-21.5 ohms. If not check for open in circuit between regulator and ECU. If wiring is good replace differential pressure regulator
No. 14 & No. 17 Potentiometer & Wiring Reading below 12,000 ohms with airflow sensor plate in rest position and altitude sensor unplugged. If not check wirings to terminals 14 & 17 for opens. If wiring is good, adjust or replace airflow sensor plate potentiometer.
No. 17 & No. 18 Potentiometer & Wiring Reading above 35,000 ohms with airflow sensor plate in rest position and altitude sensor unplugged. If not check wirings to terminals 14 & 17 for opens. If wiring is good, adjust or replace airflow sensor plate potentiometer.
No. 18 & No. 14 Altitude Sensor Reading of 21-26,000 ohms with potentiometer unplugged. If not check for open circuit in wiring. If wiring is good, replace altitude sensor.
No. 11 & No. 14 Altitude Sensor Reading of 200-38,000 ohms w/ potentiometer unplugged. If not check for open circuit in wiring. If wiring is good, replace altitude sensor.
No. 21 & No. 2 Temperature Sensor Reading of 2500 ohms at 68°F (20°C). Reading should be higher at lower temperatures & lower at higher temperatures. If not, check for open circuit in wiring. If wiring is good, replace temperature sensor.
No. 1 & No. 5 Full Throttle Switch Reading of 0 ohms with switch in full throttle position. Reading should be infinity ohms w/ full throttle switch closed. If not, check for open circuit If wiring is good, adjust or replace full throttle switch.
No. 1 & No. 13 Idle Switch Reading of 0 ohms with switch in idle position.Reading should be infinity ohms w/ switch in any open throttle position. If not, check for open circuit If wiring is good, adjust or replace idle switch.
(1) TESTING CONDITIONS: Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20-k/ohm scale. Prevent ohmmeter damage by checking ONLY terminals listed.
QUANTUM 4-CYLINDER, GOLF & JETTA RESISTANCE CHECK (1)

Ohmmeter Between Terminals Components Checked Specifications
No. 2 & No. 15 Ground Cable Bridge Reading of zero ohms
No. 2 & No. 9 M/T Models Only Reading of zero ohms
No. 2 & No. 22 A/T Models Only Reading of zero ohms
No. 7 & No. 2 O(2) Sensor Wire Shield Reading of infinity ohms
No. 2 & No. 8 O(2) Sensor & Wiring Reading of zero ohms with Green O(2) lead disconnected and grounded. If not, Green wire has open.
No. 2 & No. 8 O(2) Sensor & Wiring Reading of infinity ohms with Green O(2) lead connected to harness. If not, O(2) is defective and should be replaced.
No. 10 & No. 12 Differential Pressure Reg. & Wiring Reading of 17-22 ohms. If not, check wire 10 or 12 for open. If wires are good, differential pressure regulator is defective and should be replaced.
No. 17 & No. 18 Potentiometer & Wiring (2) Reading of less than 1000 ohms with air flow sensor plate in rest position. If not, check wires 14, 17 and 18 for open. If wires are good, adjust or replace potentiometer.
No. 14 & No. 17 Potentiometer & Wiring (2) Reading of more than 4000 ohms with airflow sensor plate lifted away from rest position. If not, check wires 14, 17 & 18 open. If wires are good, adjust or replace potentiometer.
No. 2 & No. 21 Temperature Sensor & Wiring Reading of 6-k/ohms at 32°F (0°C). Reading of 2.5-k/ohms at 68°F (20°C). Reading of 300 ohms at 176°F (80°C). If readings are incorrect, check ground line (wire 21) between intake manifold and ECU. If wiring is good, temperature sensor is defective and should be replaced.
(1) TESTING CONDITIONS: Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20 k/ohms scale. Prevent ohmmeter damage by checking ONLY terminals listed.
(2) Potentiometer terminals No. 1, 2 and 3 are connected respectively to terminals No. 18, 17 and 14 on ECU connector.
GLI & GTI VOLTAGE CHECK (1)

Voltmeter Between Terminals Components Checked Specifications
No. 1 & No. 2 Voltage Supply To ECU Battery voltage with ignition on. If not, check fuse 18. If fuse is good, check open ground circuit between intake manifold and ECU.
No. 1 & No. 2 Voltage Supply From Starter Minimum of 8 volts with starter cranking. If not, check wiring to 15 and "X" terminals reversed on relay board. See wiring diagram.
No. 2 & No. 3/No. 2 & No. 4 Idle Stabilizer Control Valve & Wiring Battery voltage with ignition on. If not, check middle (voltage supply) wire of connector for control valve. If center wire good, wire 3 or 4 to control valve is open. If wiring is good, control valve is defective and should be replaced.
No. 2 & No. 5 Full Throttle Switch & Wiring Battery voltage with ignition on and full throttle switch actuated. If not, check middle (voltage supply) wire of connector for throttle switch. If center wire good, wire 5 to full throttle switch is open. If wiring is good, full throttle switch is defective (due to no continuity) and should be replaced.
No. 2 & No. 13 Idle Switch & Wire 13 Battery voltage with ignition on and idle switch activated by throttle lever. If not, wire good., idle switch is incorrectly adjusted or bad.
No. 2 & No. 6 A/C Voltage Signal Battery voltage with ignition and A/C on. If not, check A/C fuse. If good, check wiring bridge between wires 6 and 16. Check wires 16 and 19 to A/C.
No. 2 & No. 16 A/C Voltage Signal Battery voltage with ignition and A/C on. If not, check A/C fuse. If good, check wiring bridge between wires 6 and 16. Check wires 16 and 19 to A/C.
No. 2 & No. 19 A/C Voltage Signal Battery voltage with ignition and A/C on. If not, Check A/C fuse. If good, check wiring bridge between wires 6 and 16. Check wires 16 and 19 to A/C.
No. 2 & No. 24 Wiring Between Starter & ECU Minimum 8 volts with starter cranking. If not, check wire 24 for open. If wire is good, starter solenoid switch is defective and should be replaced.
No. 2 & No. 25 Hall RPM Signal & Ignition ECU Voltage display must fluctuate with starter cranking. If not, check wire 25 to ignition ECU for open. If wire 25 good, check wiring between ignition distributor and ignition ECU. If wiring is good, Hall sensor is defective and should be replaced. If wiring and Hall sensor are good, ignition ECU is defective and should be replaced.
(1) TESTING CONDITIONS: Disconnect and ground high tension lead at ignition distributor end. Unplug ECU connector with ignition off. Set multimeter to 20-volt DC scale.
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