Pin Voltage Charts
NOTE:
All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in testing procedures. Voltage readings may vary slightly due to battery condition or charging rate. See Figure
for ECM connector pin identification
The following conditions must be met before testing:.
- Engine at normal operating temperature.
- Engine idling in closed loop (for ENGINE RUN or KEY ON column).
- ALDL diagnostic connector NOT grounded.
- Scan tester NOT installed.
ECM TERMINAL PIN VOLTAGE
| PIN & (WIRE COLOR) |
CIRCUIT NAME |
VOLTAGE READING W/KEY ON |
VOLTAGE READING W/ENG "RUN" |
| Y1 (Brown) |
Ignition Signal |
0 |
VBAT |
| Y2 (Yel/Blk) |
A/C Signal Input |
VBAT |
On-0 Off-VBAT |
| Y3 (Blu/Yel) |
Diagnostic Request |
VBAT |
VBAT |
| Y4 (Blk/Grn) |
Ground (CA Only) |
0 |
0 |
| Y5 |
Not Used |
***** |
***** |
| Y6 (Blu/Orn) |
PSPS Input |
On-0 Off-VBAT |
On-0 Off-VBAT |
| Y7 (Blu/Red) |
Test Switch |
VBAT |
VBAT |
| Y8 (Lt Grn/Red) |
Canister Purge |
VBAT |
VBAT |
| Y9 (Purple) |
Duty Cycle Terminal |
0 |
0 |
| Y10 |
Not Used |
***** |
***** |
| Y11 (Wht/Yel) |
TCC Relay |
VBAT |
VBAT |
| Y12 (Orange) |
Igniter Output |
|
.3-.2 |
| Y13 (White) |
Crank Angle Sensor Input |
0 |
1-2 |
| Y14 (Blu/Wht) |
Idle Switch |
0 |
0 |
| Y15 (Yellow) |
VSS Input |
0-5 |
0-5 |
| Y16 (Red/Grn) |
Recirc. Exhaust Gas Temp |
3.25-4.4 |
4.4 |
| Y17 (Red/Blk) |
Intake Air Temp Signal |
.5-.3 |
.5-.3 |
| Y18 (Red/Yel) |
CTS Signal |
.5-1.5 |
.5-1.5 |
| Y19 (Yel/Blu) |
O2 Sensor Signal |
0 |
0-.9 |
| Y20 (Ppl/Grn) |
Serial Data Output |
5 |
5 |
| Y21 (Gray) |
TPS Signal |
.68-1.25 |
.68-1.25 |
| Y22 (Gry/Grn) |
MAP Signal |
3.9 |
|
| Y23 (Gry/Red) |
5V Reference |
5 |
5 |
| Y24 (Gry/Yel) |
Sensor Ground |
0 |
0 |
ECM TERMINAL PIN VOLTAGE
| PIN & (WIRE COLOR) |
CIRCUIT NAME |
VOLTAGE READING W/KEY ON |
VOLTAGE READING W/ENG "RUN" |
| G1 (Blu/Blk) |
Fuel Pump Signal |
VBAT |
VBAT |
| G2 (Blk/Grn) |
ECM Ground |
0 |
0 |
| G3 (Pnk/Blk) |
O2 Heater Control |
0 |
0 |
| G4 |
Not Used |
***** |
***** |
| G5 (Lt Grn/Yel) |
EGR VSV |
VBAT |
VBAT |
| G6 (Lt Grn/Blk) |
ISC Solenoid Driver |
VBAT |
VBAT |
| G7 (Blu/Blk) |
Ignition Feed Signal |
VBAT |
VBAT |
| G8 (Red) |
Injector Battery |
0 |
VBAT |
| G9 (White) |
Battery - Back-Up |
VBAT |
VBAT |
| G10 (Blk/Blu) |
ECM Ground |
0 |
0 |
| G11 (Blk/Yel) |
Cranking Signal |
0 |
0 |
| G12 (Blk/Red) |
Clutch Switch (M/T) |
VBAT |
VBAT |
| G12 (Blk/Red) |
Park/Neutral Switch (A/T) |
0 |
0
, |
| G13 (Ppl/Yel) |
Check Engine Light |
0 |
VBAT |
| G14 (Lt Grn/Wht) |
Throttle Opener VSV |
VBAT |
VBAT |
| G15 (Blue) |
Main Relay Driver |
0 |
0 |
| G16 (Pink) |
Fuel Pump Relay Control |
VBAT |
0 |
| G17 (Yellow) |
Injector Driver |
0 |
VBAT |