ECM Main Power Relay
Circuit Diagram
Fusebox
8
1
Alarm Control
Unit
ie
-ol
le
^-ems
iometer
9 FUEL SYSTEM/ENGINE MANAGEMENT
TACHOMETER
Fault Code
Possible cause
Action
P1385
Tachometer system fault
View & note `freeze frame' data if
available.
View & note `sensor' data.
Ensure tachometer connector is secure.
Disconnect ECM and proceed to pinpoint
test 1:-
P1386
Open circuit, or short circuit to ea
rt
h
P1387
Short circuit to batte
ry
+
Disconnect tachometer and proceed to
pinpoint test 5
Pinpoint Tests
Test
Result
Action
1
Check cable and terminal integrity:
OK
Disconnect tachometer and proceed to test
-
ECM pin 62
2
Faulty
Rectify fault, proceed to test 6
2
Check cable for short circuit:
OK
Proceed to test 3
-
ECM pin 62 to earth
Short circuit
Locate and rectify wiring fault, proceed to
test 6
3
Check cable resistance:
1.1 to 1.3KQ
Proceed to test 4
- ECM pin 62 to ECM pin 1
Faulty
Renew 1.2KQ in-line resistor, proceed to
test 6
4
Check cable continuity:
OK
Proceed to test 5
-
Tachometer pin 1 to ECM pin 62
Open circuit
Locate and rectify wiring fault, proceed to
-
Tachometer pin 2 to earth
test 6
- Tachometer pin 4 to alarm control
unit pinl
5
Check cable for short circuit:
OK
Renew tachometer, proceed to test 6
ECM pin 62 to ECM pin 69
Short circuit
Locate and rectify wiring fault, proceed to
test 6
6
Reconnect harness, clear fault code and
OK
Action complete - quit test
run diagnostic tool function test to visually
verify operation of tachometer
Fault still present
Contact Triumph service
9.74