Index
Safety Precautions ....................................... 2
Vehicle Service Information ......................... 3
Visual Inspection .......................................... 3
Warranty ..................................................... 72
1. Multimeter Basic Functions
Functions and Display Definitions ............ 4
Setting the Range ..................................... 6
Battery and Fuse Replacement ............... 7
Measuring DC Voltage ............................. 8
Measuring Resistance .............................. 8
Measuring DC Current ............................. 9
Testing for Continuity ............................. 10
Testing Diodes ........................................ 10
Measuring Engine RPM (TACH) ............ 11
Measuring Dwell ..................................... 12
Measuring Duty Cycle ............................ 12
2. Automotive Testing with the CP7678
General Testing ...................................... 13
- Testing Fuses ...................................... 13
- Testing Switches .................................. 13
- Testing Solenoids and Relays ............. 14
1
CP7678
®
by
®
Digital Multimeter
OPERATING
INSTRUCTIONS
Starting / Charging System Testing ........... 15
- No Load Battery Test ........................... 15
- Engine Off Battery Current Draw ........ 16
- Cranking Voltage/Battery Load Test ... 17
- Voltage Drops ...................................... 18
- Charging System Voltage Test ............ 19
Ignition System Testing .............................. 20
- Ignition Coil Testing ............................. 20
- Ignition System Wires .......................... 22
- Hall Effect Sensors/Switches .............. 23
- Magnetic Pick-Up Coils ....................... 24
- Reluctance Sensors ............................. 24
- Ignition Coil Switching Action .............. 25
Fuel System Testing ................................... 26
- Testing GM C-3 Mixture Control
Solenoid Dwell .................................... 26
- Measuring Fuel Injector Resistance .... 27
Testing Engine Sensors ............................. 28
- Oxygen (O
2
) Type Sensors .................. 28
- Temperature Type Sensors ................. 30
- Position Type Sensors –
Throttle and EGR Valve Position,
Vane Air Flow ...................................... 31
- Manifold Absolute Pressure
(MAP)
and
Barometric Pressure
(BARO)
Sensors ..... 32
- Mass Air Flow
(MAF)
Sensors .............. 34
250V MAX
15A MAX
FUSED
COM
DC
15A
AUTO POWER OFF
CP7678
®
OFF
200
20
2
DC V
200
m
20M
200
K
20K
2K
200
8CYL
6CYL
TACH
X10
5CYL
4CYL
8CYL
6CYL
5CYL
4CYL
DWELL
DUTY
CYCLE
%
OHMS
°
20
15
A
20V