Manitowoc Grove 5540F Service Manual page 186

ENGINE AND ENGINE SYSTEMS
Code 15: The engine coolant reads too low. This may occur if the temperature is below 30° F (-1° C), or if the coolant tem-
perature sensor is unplugged.
To verify coolant temperature wiring:
1. Disconnect the coolant temperature sensor (CTS) and measure the resistance of the coolant temperature
sensor. This will vary depending on the sensor's temperature. The resistance should be within 5% of that
listed below. If the sensor differs, replace the sensor.
2. Turn ignition power ON.
2.1 Measure the voltage between the CTS sensor pin A (WHT/BK) and ground. This should read near 5
2.2 If no sensor or wiring problems are found, replace the ECM.
Code 21: The throttle position sensor (TPS) is reading incorrectly. Make sure the throttle position sensor is plugged in.
To verify the throttle position sensor and wiring:
1. Disconnect the throttle position sensor from the harness.
1.1 Measure the resistance between TPS pins A and B. This should read 2.5 - 7.5 ohms. If it is outside this
1.2 Measure the resistance from pin A to pin C while slowly, manually move the throttle plate. The resis-
2. Turn the ignition power ON. Measure voltage from harness to TPS connector pins A (-) and B (+). This
should measure 4.75 to 5.25 volts. If not proceed with step 2-1.
2.1 Perform the following measurements:
2.2 Turn the ignition power OFF. Disconnect the ECM from the wiring harness. Disconnect the MAP sensor
6-18
Degrees F (C)
-22 (-30)
5 (-20)
32 (0)
68 (20)
77 (25)
86 (3)
95 (35)
104 (40)
140 (60)
167 (75)
176 (80)
194 (90)
203 (95)
212 (100)
248 (120)
volts. If it does not proceed to step 2.1.1.
2.1.1 Turn off the ignition power and disconnect the ECM.
2.1.2 Measure the resistance from ECM pin 9 to CTS pin A. It should read less then 1 ohm. If it does
not repair the wire.
2.1.3 Measure the resistance from the ECM connector pin 10 to sensor pin B (BK/YL). It should read
less then 1 ohm. If it does not, repair the wire.
range, replace the sensor.
tance should increase smoothly without dips or spikes. If it is not smooth replace the sensor.
Published 10-21-2010, Control# 198-04
5540F/YB5515 SERVICE MANUAL
CTS/IAT Resistance
CTS Resistance (Ohms)
52594
21371
9399
3511
2795
2240
1806
1465
671
395
334
242
207
178
100.9
IAT Resistance (Ohms)
51791
21044
12073
3457
2752
2205
1778
1443
660
398
329
238
204
175
99